Alex O'Connor es un analista novato de la CIA al que se le asigna su primer caso: examinar las declaraciones de un espía ruso desertor que afirma que hay renegados dentro de su organización planeando un ataque catastrófico que pondrá a América de rodillas. Al parecer, los padres de Alex, su hermana Katya y Mark, son parte de la célula durmiente rusa a la que debe investigar.

Mark y Katya son descubiertos como espías por su hijo, Alex. Katya quiere convencer a Alex de que está equivocado, lo que les lleva a una discusión. Victor es advertido de lo que pasará si no vigila a los O'Connors. Mientras, Alex se asocia con la agente Michelle Prado como parte de una fuerza de conjunta entre la CIA y el FBI. El objetivo de Alex: desenmascarar al desertor.

A raíz de un tiroteo violento, Alex convence al FBI para entrar en una operación encubierta y encontrar el alijo oculto de Mikhail. Junto al agente Prado, Alex lidera a un equipo para recuperar un ordenador portátil de un edificio gubernamental en Filadelfia; pero Víctor ordena a los O´Connor robar el portátil antes. Mientras, Katya descubre un peligroso secreto de Natalie.

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.

Wanted in connection to Michelle's disappearance, Alex accepts help from an unlikely ally. Natalie and Victor adjust to life on the run.

The whole O'Connor clan go on the run, trying to escape both the FBI and the SVR while also plotting to expose Faber as the FBI mole.

Sam and Alex join forces to find Oscar Christoph. Victor plots to take down the Rezident.

With time running out, the O'Connors race to stop Black Dagger. Victor faces off with the Rezident. Natalie and Sarah must outsmart SVR agents to stay alive.