A burglar inadvertently becomes infected with a deadly virus. Dr. Sloan and Jesse are subsequently exposed to the virus after Jesse stumbles upon the thief's dead body. Both Mark and Jesse are confined to Mark's home while Steve and Amanda investigate the drug company that manufactured the virus, in the hopes of discovering an antidote before Jesse runs out of time.

Mark, Steve, et al, investigate a string of the so-called ""Casanova"" murders. Dr. Sloan loses his detached perspective when the killer begins calling Mark.

Mark, Steve, et al, investigate a string of the so-called ""Casanova"" murders. Dr. Sloan loses his detached perspective when the killer begins calling Mark.

Dr. Sloan investigates a photographer, the overly protective mother of Jesse's friend's fiancée, in the murder of a private investigator.

A young undercover detective investigates a militia-type organization to solve a terrorist bombing witnessed by Mark. She has to decide whether to risk blowing her cover and warn Dr. Sloan of an attempt on his life or finish her assignment.