Allegiance: Season 1, Episode 4

1 - 4: Chasing Ghosts

A shocking discovery leaves Alex struggling to reconcile his theories with the evidence found at City Hall, and Sam encourages him to keep looking for clues. Meanwhile, Mark and Katya must answer for their actions when the Rezident doubts their commitment to the cause, and Natalie learns just how lethal Black Dagger will be if they don't stop it.