Amy Shelton-White

In the season finale well-known performance artist Afsoun Hamidi (guest star Aghdashloo) is admitted to the hospital, but when the team learns that her symptoms may have been self-inflicted as part of a documentary for her latest performance piece,

As the Cohens prepare for Kirsten's 40th birthday party, Kirsten gets some news that will change her life forever. Meanwhile, Julie is having a secret love affair-and Kaitlin is doing everything she can to stop it.

The Lightman Group investigates a murder case where a woman with multiple personalities (guest star Christensen) may either be a witness or the killer. Meanwhile, the President of the United States hires the firm to interrogate a potential Supreme Court nominee.

Cooper must decide whether or not to punish Mason after he is caught stealing; Pete and Violet struggle to split time with Lucas; Addison prepares for a new baby.

The Angels Memorial doctors treat victims caught in a landslide, and a group of children come in from a camping trip with measles putting the entire ER at risk.