You are being watched.

The government has a secret system...

A machine that spies on you every hour of every day.

I designed the machine to detect acts of terror, but it sees everything...

Violent crimes involving ordinary people.

The government considers these people irrelevant.

We don't.

Hunted by the authorities, we work in secret.

You will never find us.

But victim or perpetrator, if your number's up, we'll find you.

[Female voice]

911. What is your emergency?

This is subway train operator 4827.

There's been an accident.

I couldn't stop the train in time, and I hit a kid.

I think he might have been pushed.

Open.

I want 'em held in isolation.

No contact: Not with their lawyers, not with each other, not with anybody.

This is a matter of national security.

They're terrorists?

They look more like investment bankers to me.

Well, warden, three of them may be.

But one of them is the most dangerous criminal I've ever pursued.

I can hold them for 72 hours without charging them, and I fully intend to.

Then you have 72 hours.

This is Rikers, not Guantanamo.

You don't plan on asking them any questions?

Don't worry, Carter.

We've got the DNA evidence from new Rochelle, we got the blood from the burned car, and, thanks to you, fingerprints.

He's ours.

[Buzzer echoes]

[Overlapping murmuring]

[Metallic jingling]

[Buzzer]

[Metal clangs]

[Cell phone buzzing]

How did I know the federal government would be no match for you?

As I suspect it might be compromising for you to be found with a phone, I'll be brief.

The matter is in hand, John.

We'll get you out of there.

I took too many risks.

It's my fault. I'll handle it.

Listen to me.

I made preparations for a scenario like this.

In 72 hours, you will walk free.

What if another number comes up?

Unfortunately, as I told you, they never stop coming.

I'll have to manage as best I can.

I sincerely hope our next conversation is under better circumstances.

[Overlapping murmuring]

I'll be in touch.

My name is Mr. Swift.

I'm your substitute teacher.

Ms. Benthem received a last-minute opportunity to attend an all-expenses-paid teaching seminar in Maui.

I see in Ms. Benthem's lesson plan that today we're doing... Addition.

That can't be right.

It's busywork, punishment.

We're supposed to add all the numbers from one to a hundred.

You know, in the late 18th century, there was a math prodigy named Carl Friedrich Gauss who was faced with the same tedious problem that you are.

He figured a way around it.

One to a hundred.

Who'd like to take a crack at working out Gauss' equation?

Anybody?

Mr. Phipps?

Uh...

I got to be honest, "Mr. Swifty," you lost me at "Friedrich."

[Laughter]

I'll give you a hint.

[Class bell rings]

[Overlapping murmuring]

[Cell phone rings]

Fusco.

Good morning, Detective.

I trust that you received my email?

And the entire roll call for Brooklyn science.

I need you to tell me everything you can about Caleb Phipps.

Couple run-ins with the NYPD.

Typical kid stuff.

Nothing exceptional.

I'll say.

2.6 gpa and test scores that sit squarely in the mid-range.

He spent my whole class doodling in his notebook.

Hey, you still there?

Please continue.

One thing did come up.

Caleb had an older brother Ryan, killed two years ago in a subway accident.

Kid was drunk.

Slipped on the tracks and got clipped.

Sounds awful.

Any further details?

I'll pull the incident report.

Now Caleb lives alone with his mom.

She's an administrative assistant in Kensington.

Hey, Caleb.

You going to that party saturday?

Uh, no, that's not my kind of thing.

Oh.

Besides, I'm heading out of town.

Taking a trip.

[Overlapping murmuring]

They never seem to stop texting.

Beginning to feel like I'm on another planet.

Get used to it.

Their planet's gonna be running ours in about ten years.

High schools are different nowadays.

Gang fights, drug searches, and pregnancies.

This kid could be into anything.

[Cell phone camera shutter clicks]

You weren't exaggerating about the drug problem.

Kids ain't what they used to be.

Be careful in there, pal.

I-I won't even ask.

Probably best.

Besides, we have more urgent matters to discuss.

Our friend in Rikers.

I have the situation in hand.

I don't want you crossing some kind of line to do...

This?

Already deleted them from the network too.

That line you're talking about, I crossed it a long time ago.

Now we have to deal with the DNA sample.

FBI keeps it in a secure lab here in New York.

I know what to do.

But I'm gonna need a couple things from you.

[Over P.A.]

This is principal Lawton, reminding you that the Brooklyn school of science & humanities closes promptly at 5:00 P.M.

Thank you.

Mr. Swift.

[Door shuts]

A word, please.

It has come to my attention that you tried to show Ms. Benthem's students how to get around one of her assignments.

Well, the assignment seemed a bit remedial.

I was hoping to teach...

Teaching is Ms. Benthem's job.

Your job is to ensure that her students do the work that she prepared.

Don't sweat Lawton.

She thinks schools would run better if they just got rid of the students and teachers.

Chris Beckner, computer science.

Harold Swift.

Nice to meet an idealist.

No, no, not me.

Throw all this stuff online, I say.

Let me teach in my boxers.

Run wild, man.

[School bell rings]

I believe I will.

[Cell phone chime]

Yes, Detective Fusco?

Do you have some new information for me?

Yeah, as a matter of fact, I do.

I took a look at the report of his brother's death.

Caleb was the only witness.

He was there?

His brother died right in front of him?

Yeah, but something's not right.

I looked at every incident report that night.

The transit cop called for a backup, to dispatch, and then canceled the request.

Why would a policeman rescind a request for backup?

That's what I'm trying to figure out.

I'm waiting on the transcripts to find out why.

Maybe it's time I go meet Caleb's mom and find out what his home life is like.

Interesting.

Caleb's latest national aptitude test score is exactly 50%.

A statistically improbable score.

Unless you try to get it.

You see, Caleb knew the answer to every question.

But he chose only to fill in every other one.

I don't get it. He tanked on purpose?

Why would you want to hide the fact you're a genius?

Why, indeed?

Caleb, a word?

I couldn't help but notice this.

No offense, Mr. Swift, but now you're going through the garbage?

[School bell rings]

[Murmuring fades]

Pi.

Can any of you tell me what it means?

I'll settle for an intelligent question here.

My friend has a question, Mr. Swift.

"What is any of this good for, and when would we ever use it?"

[Laughter]

Let me show you.

Pi.

The ratio of the circumference of a circle to its diameter.

And this is just the beginning.

It keeps on going.

Forever.

Without ever repeating.

Which means that contained within this string of decimals is every single other number.

Your birth date, combination to your locker, your social security number.

It's all in there somewhere.

And if you convert these decimals into letters, you would have every word that ever existed in every possible combination.

The first syllable you spoke as a baby, the name of your latest crush, your entire life story from beginning to end.

Everything we ever say or do...

All of the world's infinite possibilities rest within this one simple circle.

Now what you do with that information...

What it's good for...

Well, that would be up to you.

[Knock on door]

NYPD, ma'am.

We're investigating a string of burglaries in the area.

Talking to residents about things they might have seen or heard.

Mind if I come in and ask you a few questions?

I'm running a little late.

So you, uh, you live alone?

With my son Caleb.

We don't have a lot of room, so Caleb takes the couch.

[Cell phone rings]

Uh, that's work. Just give me a sec.

So you and your son see anything suspicious lately?

Any strange comings and goings?

Anyone who stands out?

Nothing I can think of.

Cops come a few times a year.

It's domestic stuff mostly.

Some families have it rough, you know?

Yeah, I know exactly what you mean.

Thanks for your time.

[Door opens]

[Static, voices]

Yes, Detective?

I planted that webcam for you.

Met Caleb's mom.

[Sighs]

Late for work, rolling out the door with the shakes.

My guess is she's hitting the bottle.

No wonder Caleb doesn't care about his grades.

Anything new on our two dealers?

Diego Velasquez and Ronnie Samms.

Used to deal for a guy by the name of Lorenzo.

Type of guy you don't wanna cross.

But now they're working for some new up-and-comer that narcotics hasn't been able to identify.

I tell you, that school's a real minefield.

Okay.

[Door slams]

Gonna keep your mouth shut, right, chief?

Yeah, sure.

[Sighs]

Except to say this.

The next time you decide you want to deal E to a kid who's clearly never bought in his entire life, do it in the locker room downstairs, because this jumpy fool is a neon sign shouting "drugs ahoy"... Chief.

That's enough!

Unless you want to settle this in the principal's office.

Are you okay?

I don't need your help... okay?

"Hacker" used to refer to industrious coders who pushed the boundaries of modern computing.

Then that word became misappropriated by those who pushed the boundaries so far that they ended up with jail time.

Like Kevin Mitnick, back in the 1980s.

He was just trying to see how stuff worked.

Mitnick was looking for flaws in the system.

And he did so by breaking the law.

But he proved people were the flaw, not the code.

Now they're paying him millions for the same thing that got him locked up in the first place.

[Laughter]

Perhaps the most notorious hacker of them all was the one that got away.

Back when Uncle Sam was trying to maintain IriTrip on the budding Internet...

Or Arpanet, as it was known then...

This hacker, this coder, hacked into the system and laid its secrets bare, ensuring that the Internet would become an open forum.

Plus that hacker made his mark without ever getting busted.

True.

Whoever it was, that person's still out there.

[School bell rings]

[Cell phone buzzes]

Hey, I'm checking on the boy genius.

Not you, the other one.

Turns out he's quite the little coder.

He's been coding a massive program.

In longhand, he doesn't have a computer at home.

Then he writes it into a computer in the lab.

If the partial code I've discovered is a snapshot of his work... What he's creating...

Could be groundbreaking.

Detective Fusco, can you do something for me?

I need you to follow Diego and Ronnie.

Caleb had a run-in with them today that might lead to trouble.

Is there a history there?

Hard to tell.

But Caleb seemed to take an outsized interest in their drug dealing.

If someone's pulling their strings, I'd like to know who.

Finch, whoever this drug dealer is, he's careful.

[Cell phone chimes]

Detective, how goes phase one of your plan?

I got the package you sent over, but if I'm gonna wade in this pool, I need the right specs.

Yeah.

Sending them to you now.

Our friend in Rikers is counting on you.

Okay.

Knock 'em dead, Detective.

They won't know what hit 'em.

[Mellow club music]

Wow.

Hi, I'd like to have... The first one, on me.

How are you doing?

Thanks, but, um, I'm looking for something a little more... Specific.

Detective Fusco, our Young man is on the move.

Give you a ride home?

Car is right down there.

I'd like that.

I have to admit, you kind of threw me at first.

Asking all those questions about my background, my health.

I couldn't tell whether we were flirtin' or fillin' out my medical history.

I'm a practical girl.

I like to know what I'm getting into.

[Giggles]

So are we... Getting into anything tonight?

I am.

Ooh, I don't know what happened, but...

I didn't even have that much to drink.

Yeah.

[Clicks tongue]

Open wide, big fella.

I've been following this drug money all night.

Diego and Ronnie handed a bagful of it to a homeless guy, who I followed till he dumped it off at a money transfer place.

The worker there wired it to another money hub across town, where I hoofed it over there just in time to see some other guy pick up the cash and drop it in a P.O. box right here in crown heights.

Our mysterious drug lord is laundering his money, making it untraceable.

Well, not untraceable enough.

Whoever comes in for this cash is our guy.

Where are you anyway?

I'm looking at you.

Thought you were following the kid.

I am.

Here you go, sir.

Thanks.

Well, I'll be damned.

Our mystery drug lord is Caleb.

Graded your quizzes.

Some of you have been paying attention.

Caleb, I expected better.

Pssh.

[Cell phone rings]

What did the kid do now?

Caleb just got a message.

He's supposed to meet his supplier at 2:00.

We have to follow him.

Tricky little bastard, keeping his identity a secret.

He's better than most dealers twice his age.

I'll be sure and tell him how impressed you are with his criminal aptitude.

[Class bell rings]

Beckman just broke into Caleb's account, Detective.

He copying a file named 17-6-21 onto a thumb drive.

Whatever Caleb's making...

His teacher's interest in it... Is far from academic.

[Overlapping murmuring]

Oh, Mr. Phipps!

Look, I'm kind of on my way somewhere.

I just wanted to return something of yours.

You dropped this yesterday.

You really got to stop going through the trash, Mr. Swift.

You know, I used to do a little coding myself.

That's an elegant string you have.

But it occurs to me that if you want to implement multi-threading, you'd do better to use atomic variables.

Just a thought.

Wait, that... That works.

Yes, that's why I suggested it.

Uh, thanks.

I hope you have your service weapon with you, Detective.

Yeah, I got you a machine gun too.

Very funny, Detective. Let's try not to lose him.

Yo, Roman.

You here?

[Moaning]

Oh, jeez.

[Triggers clicking]

Whoa.

That's what you came for, right?

So tell me...

Why would a kid like you do something so stupid like dealing at a school in my neighborhood?

That's Lorenzo, all right, Diego and Ronnie's old boss.

What's the plan?

Crap.

You know, before he had his little accident here...

Roman was telling me how you're just trying to score some bank to take a big trip.

That true?

Yeah.

You pay back every dime you made selling to my customers, I'll let you leave town intact.

Be back here tomorrow night, 8:00 P.M., or I'll come find you.

How do you expect me to score that kind of cash in a day?

Relax.

All right, I'll... Rob a bank or something.

I like you.

You got brass.

But you don't show tomorrow night...

Break a lot more than your legs.

Kid's got it tough.

But picking a fight with a drug dealer?

A dumb move for a genius.

Why would a Young man with such potential risk it all just to get some easy drug money?

I don't think it's about the money.

I think it's about the brother.

[Paper rustling]

Dispatch transcripts from the night Ryan Phipps died.

Now the transit cop who filed the report called for backup...

Because Caleb initially reported that two youths got into a shoving match with Ryan, pushed him onto the tracks.

But the officer canceled the backup call and filed an accident report instead.

Why would Caleb change his story?

Maybe he knew the killers.

Maybe he was thinking about taking care of them himself.

Diego and Ronnie?

He's manipulating those morons.

Got 'em running drugs for him, and they don't even know it.

What's Beckner so absorbed in?

That's Caleb's work.

[Line rings]

Howard, it's Chris.

Can you still meet up tonight?

I think you'll be impressed with what you see.

Great. I'll see you there.

Change of plans, Detective.

Let me guess.

You need me to keep an eye on little Einstein, myself, tonight.

Keep me posted.

[Static, voices]

So, Mr. venture capital firm partner...

Junior partner.

Long way from the corner office.

Still have to watch my step.

Pick my projects carefully.

I get it.

When you see this...

Well, then, let's... Let's just see it, Chris, so I can get back to my wife and kids.

[Sighs]

[Computer trilling]

What the hell was that?

The library of congress.

What?

235 terabytes on... On one thumb drive?

The Internet's choking on streaming video.

They're gonna need a new compression algorithm to continue growing.

And I've got it.

All I need is an investment from a firm like yours to help me get it off the ground.

So... here's the thing, Chris.

I remember your code from back in college.

You were a medium talent at best.

There is no way that that Chris Beckner designed something this extraordinary.

Unlike our old friends, I didn't peak in college.

So no one else knows about this project?

Programmers? Developers?

No other entanglements?

I can guarantee it.

Well, let's hope so.

Because I would hate for anyone to come between you and what I believe is going to be a very large check.

[Beep]

Finally tracked down that transit cop, Murphy.

The one who was first on the scene when Caleb's brother died. Left a message for him to come down to the eighth after his shift.

Speaking of which, where's the kid now?

He's moving money around, large amounts.

Getting the cash to pay off Lorenzo?

No, he set up some kind of a trust, and he's pouring all his money into it.

Maybe he's thinking about taking that trip he's always talking about.

[Cell phone buzzing]

Beckner just texted Caleb.

He wants to meet at 8:00 tonight.

The same time he's supposed to meet Lorenzo.

And quantum physics notwithstanding, he can't be in two places at once.

Unless I'm right, and this kid's got a plan, time's running out on two fronts.

Maybe skipping town's the best thing for him.

Then we could focus some on getting your pal out of lockup.

Mr. Reese can take care of himself, Detective.

And right now, he's in very capable hands.

Detective Carter, time is ticking away fast for our friend in Rikers.

Don't worry. I know what to do.

[Over computer]

Here you go.

Mm. Sorry, honey.

I'll be better tomorrow.

I promise.

Yeah.

Everything's gonna be better tomorrow, ma.

Detective Fusco.

I just want to remind you that I need your help tonight.

Caleb has two appointments, and we have no idea which one he intends to keep.

I'll be there.

You wanted to speak with me?

Yeah, have a seat, officer Murphy.

Like I said, I'm, uh... Working on a cold case.

Commuter got pushed.

Looking for related cases, this popped up.

Ryan Phipps.

Says here you were first on the scene?

Yeah, that's right.

Kid was six months shy of his 18th birthday.

Coming home with his little brother Caleb.

Ryan was horsing around, drinking a little bit.

Slipped on the tracks and got clipped.

Yeah, yeah, I remember.

It was a rough one.

Because it was a kid?

Or because you didn't report the whole story?

I know about the kids who pushed Ryan on the tracks.

I'm no Detective, Detective.

I'm just a lowly transit cop.

I seen a lot of things in my time.

And I made a lot of decisions I regret.

This is not one of those times.

You may regret it when Caleb becomes a killer.

What are you talking about?

You think revenge is gonna make Caleb feel better about seeing his brother die?

You're a long ways off, Detective.

Then give me some directions.

You know, I did to the kid what you're doing to me right now.

When I asked him for descriptions of the other kids... Kept changing it up.

There were no other kids.

[Quietly]

No.

Just two brothers drinking.

Bored.

Waiting for a train to go home.

So they dare each other to, uh... cross the tracks.

You know, how many times you can cross back and forth before a train comes?

Well, Ryan doesn't want to lose to his little brother.

One kid makes it, the other kid doesn't.

I don't know who got the better deal.

So I told him I'd leave all that out of the report, write it up as an accident, and for him to keep it to himself.

So no matter what he had to tell his mom...

Or the cops, or God himself...

Nothing was gonna bring his brother back.

What can I tell you?

Some things you can't fix.

[Cell phone rings]

[Beep]

Hey, I just talked to Murphy.

The brother's death was an accident, but it sounds like Caleb blames himself for it.

Well, that's a problem, Detective, because I lost Caleb.

He got on a city bus, and it left before I could catch up.

You're kidding me.

May I remind you that of the many things I'm equipped to do, pursuit would not be chief among them.

Our only option now is to wait for Caleb at the two places he's likeliest to turn up.

I'll stake out beckner at the High School.

You keep an eye out for our aggrieved drug dealer.

Get everyone, and hunt that kid down!

[Line dials]

Our boy is a no-show, and Lorenzo wants his head.

You worry about the kid.

I'll take care of Lorenzo.

[Panting] He's not here either, Detective.

I may be too late.

Swift, what are you doing here?

I was gonna ask you the same.

I-I left some papers on...

Stop it!

I saw you break into Caleb's account and copy his files.

Is that what you're willing to stoop to?

Stealing the work of a student and passing it off as your own?

I am not gonna stand here and be accused of plagiarism by some substitute teacher.

Besides, why would I copy work off of a "C"-grade student?

Because Caleb is anything but average.

And you know it.

That's why you took his work to your friend.

Caleb... Approached me a few months ago about this project he was working on.

I was skeptical, but when I... saw his code I couldn't believe my eyes, so I decided to help him.

By cutting him out of it.

No.

All he wanted was some money up front for this trip that he wants to take.

Said he didn't even want any credit.

Why on earth would you agree to that?

I didn't.

Read it for yourself.

Caleb gets all the credit.

It was just easier for me to...

Pitch the idea with him myself...

Get some capital...

And then reveal the true brain behind it.

He offered me half if I put the other half in a trust that he set up for his mom.

But I'm giving him the whole thing.

All the money from 17-6-21.

17-6-21?

It's the name he gave the program.

He said it was some kind of dedication.

Look, I am telling you, six months from now, Caleb is going to be the richest 18-year-old in the country.

No.

No, he won't.

Dispatch? Officer Murphy, regarding the subway fatality. on the backup request.

10-5, officer. Cancel backup request?

Affirmative.

This seat taken?

What are you doing here?

You're so smart, Caleb.

Ask me something you don't know.

The thing about being reckless...

Taking chances...

Is that you make a lot of mistakes, cause a lot of grief.

Gonna start lecturing me on mistakes?

How I need to live and learn?

Move on?

That's really inspiring, Mr. Swift.

I'd stand up on my desk and clap for you.

But... No.

Your mistakes, like mine, are part of who you are now.

You can't move on from that.

Believe me.

I've made a sizable number.

But... Sometimes your mistakes can surprise you.

My biggest mistake, for instance...

Brought me here.

At exactly this moment...

When you might need some help.

17 years, 6 months and 21 days into your life.

The age at which your brother died.

The age you've chosen to end your life too.

17-6-21.

So, you see... Maybe you and I are connected.

Two reckless people.

Yeah? Then what's the use?

We're just gonna keep breaking things...

Over and over.

Why not save everyone the grief?

The thing about the world is that it doesn't have any extra pieces.

It's like pi. It contains everything.

You remove a single piece... No circle.

Your recklessness, your mistakes, are the reason why, when they say "you can't change the world," you won't listen.

The world is better off with both of us in it, Caleb, rather than the alternative.

Yeah? You sure about that?

Yes, and your mom is better off with you in it.

If you think money can replace you...

You haven't seen the whole equation.

Take it from someone who thought that leaving would make it easier on everyone...

And then learned otherwise.

[Subway train rumbling]

[Rumbling fades]

[Dramatic music]

♪

Say it to me again.

Slowly.

According to the lab results, none of the DNA we took from these four men matches any of the DNA in our database.

They're clean, sir. All four of 'em.

I want every one of those samples sent to Quantico, reviewed through codis, and inspected for tampering.

They got to it.

I don't know how, but those bastards got to it.

Go.

One more thing.

Get me Carter.

You really ought to be more careful with your code.

Thanks.

I grew up during the Cold War...

When computer networks were just a gleam in the eye of the department of defense.

Things seemed more black and white then.

Arpanet was the new frontier.

Till a kid with a homemade computer turned the whole thing inside out.

All I'm saying is... It's a new era now, and things are about to get really weird.

So you should keep your code close to your vest.

And pick your friends wisely.

Pi.

The first 3,000 digits.

My number's in there somewhere.

You're smart, you'll figure it out.

Wait, uh, the hacker.

The one who got away?

How'd you know he did that with a homemade computer?

I've read all that research. No one's ever mentioned that.

I must have heard it somewhere.

Detective Carter?

Has our friend in Rikers been released?

Almost. I'm going to meet him now.

[Keys jingling]

Your DNA wasn't a match for whoever they're looking for.

We'll be processing you out momentarily.

[Gate buzzes]

Stop right there.

These men have all been classified as "unlawful combatants" by the AUMF.

Until we can establish that they're not a threat to national security, they're not going anywhere.

[Paper rustles]

Put him back.

Just the person I wanted to see.

What is going on?

I thought the evidence cleared these guys.

The DNA, the fingerprints, it's all too neat.

I've been burned too many times trying to bring this man to justice.

There's only one person that I know I can trust anymore: You.

You've been chasing him from the beginning.

And we've only got one shot left at him, Detective.

If he walks out of here, we're never gonna see him again.

I know you were a senior interrogator in Iraq.

It's time to put those military skills to use.

I want you to interrogate every last one of these men.

Find out who they are, what they know.

Start with him.