'Citadel' Reveals a Wild Twist about Ashleigh Cummings's Abby
'Citadel' Episode 4 "Tell Her Everything" reveals Abby Conroy (Ashleigh Cummings) was actually a spy named Celeste who posed undercover as Brielle before Mason Kane (Richard Madden) wiped her memory to protect Nadia Sinh (Priyanka Chopra Jonas).