When the FBI discover a mysterious ciphered document, they call in one of the best cryptanalyst: Will Scott. As he tries to balance fatherhood and his work, what he deciphers puts his own life at risk.

Will tries to figure out who Kurt was working for, and he returns to Claire's so they can crack the rest of the ciphered list together. Other ominous, interested parties give the FBI investigation team reason to be concerned about who this crypto-analyst "Will" actually is and which side he's on.

Will reconnects with daughter Anna and she promises to keep his secret. The FBI talk with Will's ex-wife and daughter and their frenzy to catch Will increases when Will and Claire slip up and blow their cover. Meanwhile, Will deciphers the next target on The List.

When the FBI locates a copy of the list, they bring in a new cryptographer to crack the code. Will visits a hacker friend and discovers a new lead to unlock Kurt's phone, which reveals new information about Claire.

Claire reveals her true colors and who she works for, and her boss Chris kidnaps Anna so Will feels the pressure to solve the rest of the code. Will returns to the FBI team when he realizes he can't keep going it alone, but both parties struggle to trust one another.