SYDNEY AND VAUGHN RISK LOSING EVERYTHING AS THEY CONTINUE THEIR SEARCH FOR THE TRUTH ABOUT VAUGHN'S FATHER, JACK AND SLOANE MYSTERIOUSLY CONSPIRE WITH EACH OTHER -- AND AGAINST SYDNEY AND VAUGHN -- AND JACK FACES A POTENTIALLY DEADLY CHOICE THAT WILL FOREVER CHANGE HIS LIFE AND SYNDEY'S, ON ABC'S "ALIAS"

"Nightingale" - Sydney and Vaughn risk their lives and careers searching for the truth about Vaughn's presumably deceased father. Meanwhile, it's unclear why Jack and Sloane seem to be conspiring with each other and against Sydney and Vaughn, and Jack faces a potentially deadly choice that will forever change his life and Sydney's, on "Alias," WEDNESDAY, APRIL 6 (9:01-10:02 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, Greg Grunberg as Eric Weiss and Mia Maestro as Nadia Santos.

Guest starring are Elya Baskin as Dr. Josef Vlachko, Robin Sachs as Hans Dietrich, Marat Oyvetsky as prisoner, Zena Leigh as beer maid, Michael Kenneth Williams as Roberts and Andrew Kirsanov as Christof Goedde.

"Nightingale" was written by Breen Frazier and directed by Lawrence Trilling.

"Alias" is broadcast in 720 Progressive (720P), ABC's selected HDTV format, with 5.1-channel surround sound.

A TV parental guideline will be assigned closer to airdate.