Now that Henry has intervened and spared Annie from the FBI's investigation into Seth's death, Annie has a new set of problems. During her confrontation with Henry, he dropped a bombshell: Auggie's former CIA wife and partner Helen might not be dead after all. Though a stunned Auggie can't believe it, the shocking revelation turns out to be true. And not only is Helen alive, but she's the same mysterious dark-haired woman who's been working with Arthur.
When Annie and Auggie question Arthur, he admits that he's been supervising Helen's off-book missions for the past seven years. And thanks to Helen's work investigating arms traffickers, she has supplied him with some valuable intel: Henry Wilcox was behind the disappearance of the five missiles during Annie's recent mission in Vienna, and he's about to take possession of them. Knowing that Henry will try to use the weapons against him in some way, Arthur sends Helen and Annie to Lyon to get to the missiles before Henry does.
Meanwhile, back in D.C., Auggie solicits top-secret help from his tech buddies to decode the image found on Seth's flash drive, and Calder develops suspicions about Annie after looking into the records from her recent mission in Vienna. And as Annie and Helen work together in Lyon, it becomes clear that her return and Henry's constant machinations are creating their own complications. Can Annie and Auggie's relationship withstand these new challenges, or could this be the end for them?