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.

When Tony opens a letter releasing a mysterious powder from inside, he and Kate are put into biohazard isolation as a precaution.

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

The return of the blue-paint serial killer, who got away once before, troubles Grissom as the team investigates the murders of four college students.

A routine traffic stop turns into a high-speed chase through the streets of Las Vegas, and when a police officer is killed, the team must evaluate the ballistics evidence to determine whether his death was a result of friendly fire.