Mark and Amanda are assigned to the task force investigating an airplane crash. An adversarial FBI agent and Russian mobsters make their assignment more difficult.

Jesse finally reunites with his father. After they narrowly elude an assassin, Jesse begins to realize his father isn't the accountant he's always claimed to be, but rather a spy. The Travis's attempt to discover who's sending the killers.

Dr. Sloan investigates to find out who's behind the death of a driver in a speedway crash.

The Matthews family is reunited after years apart. Here, Ryan and Tess Matthews come to LA to help Kate when she's in trouble with a con man.

Shadowy figures haunt Jesse after he returns after being missing five days and believes aliens may have abducted him. Mark and Steve try to figure out what happened to him, while Jesse tries to stave off hallucinations, clandestine midnight meetings, and secretive government agents.

Steve investigates a series of seemingly unconnected murders committed by terminally ill patients, to find the hidden thread.

A serial murderer strikes Community General every hour on the hour, choosing victims who've been seriously injured but 'brought back to life'.

Mark matches wits with a murderous network executive.