Diagnosis: Murder

When George Lawson, a former medical student who of Mark's, was diagnosed with schizophrenia is found at a murder scene without an alibi, Mark, Jesse, Steve, and Steve have the large task of proving he had nothing to do with the crime. Through the course of their investigation, Mark discovers that the jilted wife of the man who was having an affair with the victim's wife knows more than she's letting on about what happened. As a result, they turn to George and his coded messages for help in solving the crime.

After Steve gets in a bad accident and is saved by Jesse, he has to spend a few days in the hospital to recover. However, still slightly under the effects of anesthesia, Steve witnesses what he believes to be a murder and tries to get Mark and the others to believe what he saw. He then begins to investigate and soon discovers that the murder involves a respected doctor who appears to have a few secrets he was trying to keep hidden.

One of Mark's med students, Alex, is a contestant on a Big Brother type reality show, hoping to win the grand prize so he can use it to pay off his student loans. When a fellow contestant ends up murdered, Mark takes the victim's spot on the show, with the hopes to find out the killer, he finds out the real reason why the contestant was targeted and how the killer almost got away with their crime.

When two fashion designers hold their wedding on the catwalk before a show, things turn explosive when a bomb goes off and ultimately kills the groom. Through the course of Steve and Mark's investigation, they soon discover that the reason why the groom was targeted had to do with his planning on turning state's evidence in a drug kingpin's upcoming trial and that one of his models might know more than she's letting on.

After an elderly misanthrope dies at Community General, Jessie and Amanda find themselves in a unique situation – heirs to the old man's fortune with four other people. However, there's a catch: the will is set up in the form of a "tontine," going to the last surviving heir. As a result, all the heirs start having mysterious accidents, and ultimately all but Jesse and Amanda end up dead. Before an apparent killer can turn their sights on to his friends and colleagues, Mark aids Steve in finding out whether the old man had a living relative who was trying to get their hands on the fortune.

A filmmaker friend of Alex convinces him to let him work on a documentary about a nurse who disappeared from Community General twenty five years ago under mysterious circumstances. When the filmmaker goes to Mark with blood found in the course of his investigation, they soon suspect that the hospital could be haunted and that the filmmaker has a connection to the nurse.

Dr. Sloan's daughter goes missing on her way to LA for a family get-together. Everyone brushes it off due to her personality, but her father is adamant in thinking something have happened to her and finds himself investigating her disappearance in a small town where everyone seems unfriendly and secretive.