Katya manipulates Alex and makes him think he's mistaken when he almost exposes his parents as spies, but her lies lead to a rift in the family. Meanwhile, Victor is warned to keep the O'Connors under control and Alex teams up with an FBI agent.

In the aftermath of a violent shootout, Alex must convince the FBI to risk a dangerous covert operation to find Mikhail’s hidden cache. Meanwhile, Katya discovers one of Natalie’s most dangerous secrets, and forces her to choose between love and family.

A surprising discovery leaves Alex reeling as he tries to adjust his theories in light of what he found at Philadelphia City Hall. Meanwhile, the Rezident questions Katya and Mark's dedication and Natalie discovers the dangers of Black Dagger.

The FBI think they have a mole, so an investigation gets underway, and it puts Alex at war with his own ethics. Elsewhere, Victor devises a new method for staying on top of the O'Connors and Natalie makes a grievous error while searching for a lead.

Natalie relies on an outsider to obtain crucial info for her. Meanwhile, Sam and Alex make a dangerous move to detain an SVR source and Katya implores Alex to give her some breathing room with the task force, which leads Alex to confront Victor.

The O'Connors send the task force on a wild goose chase to Italy, while Alex tracks down the Black Dagger triggerman.

Victor spies on the Rezident, Alex reveals a big secret to Michelle, and Sam grows increasingly suspicious of the boy genius.

Michelle's shooting puts Alex at odds with the task force. The Black Dagger triggerman makes his next move.