When the FBI's Witness Protection database is hacked and the identities of several witnesses are compromised, Cyber Com is asked to investigate. In particular, two witnesses have gone missing, leading our team to theorize that the villain who hacked the database is blackmailing and using them to carry out some kind of act of terror. Given the backgrounds of the witnesses, Lillian believes they are planning a sarin-like gas attack in San Francisco and joins Gabriel and Riley in the field because her daughter Samantha lives there. Lillian's relationship with Samantha is strained and she struggles with whether or not she should tell Samantha why she is really there. Having just dealt with Amelia's death, Gabriel urges Lillian to tell Samantha the truth. Gabriel and the team track down the identity of the hacker, but are surprised when they discover that the man, Cain, is a feeble, wheelchair bound old man suffering from a debilitating disease. Unable to move and trapped in his own body, Cain was using the gas attack to exact revenge on a pharmaceutical company who gave up seeking a cure for his disease.