From ABC Medianet:

JACK IS FACED WITH A SERIOUS DILEMMA WHEN A MYSTERIOUS WOMAN
-- WHO CAN HELP HIM SAVE SYDNEY AND VAUGHN FROM FACING A FIRING
SQUAD AS FOREIGN SPIES -- REFUSES TO PUT A RESCUE PLAN IN MOTION
UNLESS SLOANE IS ASSASSINATED, ON ABC'S "ALIAS"

Isabella Rossellini Guest Stars as Katya -- the Mysterious Woman

"Crossings" - Jack contacts a mysterious woman (Isabella Rossellini) with ties to Irina to help him free Sydney and Vaughn, who have been captured and face a North Korean firing squad. But Jack is faced with a curious conundrum when the woman tells him that she will not put the rescue plan in motion until he fulfills a favor - assassinate Sloane -- on "Alias," SUNDAY, JANUARY 18 (9:00-10:00 p.m., ET), on the ABC Television Network.

"Alias" stars Jennifer Garner as Sydney Bristow, Victor Garber as Jack Bristow, Ron Rifkin as Arvin Sloane, Michael Vartan as Michael Vaughn, Carl Lumbly as Marcus Dixon, Kevin Weisman as Marshall Flinkman, Melissa George as Lauren Reed, Greg Grunberg as Eric Weiss and David Anders as Mr. Sark.

Guest starring are Isabella Rossellini as Katya, Griffin Dunne as Leonid Lisenker, Byron Chung as Colonel Yu, Leo Lee as Mr. Kwan, Arnold Vosloo as Mr. Zisman, C.W. Pyun as Ki-Jong, Francois Chau as Mr. Cho, Emma Bering as Sloane's secretary, Randall Park as Korean soldier and John D. Kim as soldier no. 1.

"Crossings" was written by Josh Appelbaum & Andre' Nemec and directed by Ken Olin