Ty Upshaw

Martha and Castle are held hostage by bank robbers dressed in hospital scrubs; Beckett's rescue efforts are hindered by a strict hostage negotiator (Dean Norris).

Jack finds Kyle Singer's residence, but Kyle, unknowingly in possession of the deadly virus, is gone. Meanwhile, as President Palmer prepares himself for the upcoming televised debate, Wayne forces him to consider some serious allegations against Anne which have surfaced; and a technical specialist (guest star Andrea Thompson) is brought in by CTU to play a critical role in dealing with the viral threat.

The agents search for a killer who seemingly possesses the ability to see through walls.