Darren McCarthy

Darren McCarthy was an employee at defense contractor Elegra Global who sold five Soviet suitcase nukes to Abu Fayed in Day 6.

Before Day 6
When Dmitri Gredenko supplied Soviet Suitcase Nuclear Devices to BXJ Technologies, Graem Bauer hired Darren McCarthy to oversee the dismantling of the five nuclear bombs. Graem also assigned McCarthy to recycle the bomb's components into nuclear energy production. When terrorist Abu Fayed offered McCarthy 3.5 million to obtain the bombs, McCarthy sold them, but didn't knew when Fayed planned on detonating them.

Day 6
After a suitcase nuke went off in Valencia, Los Angeles, McCarthy deleted his computer files and planned on heading to Las Vegas, to ignore the fall out of the explosion. When Fayed contacted him and offered him 6.5 million if he can find an engineer, McCarthy decided to accept the terms.

Before finding the engineer, McCarthy picked up his girlfriend Rita, who was unaware of McCarthy's business dealings and wanted to leave the city immediately. When rita began to demand for answers, McCarthy pulled over and demanded for her to leave. Rita then changed her attitude and realized how much money they would get, if McCarthy went forward with the job.

McCarthy checked into a hotel room and started working on finding the engineer. Eventually he discovered that Morris O'Brian would be able to trigger the nukes, but he wouldn't do it willingly. McCarthy staged a report that Morris' brother Timothy was injured and brought to the hospital, in order to draw Morris out of the CTU Los Angeles building.

Eventually CTU found out McCarthy found an engineer and Morris discovered who it was, but he left CTU before it was revealed that he was the engineer. When Chloe O'Brian contacted Morris and told him that the hospital report was doctured, Morris began to turn around. McCarthy arrived and shot at Morris' car, and he then kidnapped him.

Trivia

 * Eddie Izzard, who was originally supposed to play the role of Darren McCarthy, dropped out after only one day of filming due to scheduling conflicts.