When a supposed air marshal is murdered on a flight to the District of Columbia, Mac searches the plane for the killer and the murder weapon.

In the one hundredth episode of CSI: NY Mac faces his most deadly foe yet. There is a serial killer loose in New York City killing people with the name Mac Taylor making Mac a target.

When transferring Robert Dunbrook's son from prison to court, the NYPD is ambushed by a group of professional kidnappers who kill a member of the team and one of the CSI's lives hangs in the balance.

The Compass Killer is back, and adds yet another to his circle of victims -- but this time the CSI squad knows his name; Flack's alcoholism threatens to derail his career...