The identity of the mysterious "St. Aidan" forces Sydney to pull a stunned Will out of witness protection. But the pursuit sends the two old friends on a collision course with Allison -- the woman who ruined both their lives. Meanwhile, a zealous Lindsey arrests Jack and Vaughn as conspirators in Sydney's escape from NSC custody, Sloane, still under pressure from Lindsey, puts a plan in motion to eliminate Sydney, and Dr. Brezzel has an unpleasant run-in with Sark.
Elenco: Jennifer Garner , Ron Rifkin , Carl Lumbly , Kevin Weisman , Victor Garber , David Anders , Michael Vartan , Greg Grunberg , Merrin Dungey , Bradley Cooper , Rachel Nichols , Lena Olin , Melissa George , Amy Acker , Johnny Trí Nguyễn .