Blake wants to operate on Lola to prove the healing power of laughter; Glenn gets revenge on Cat's new beau; and Chief undergoes surgery.

Lola returns from the grave; Cat goes into labor as Nicky takes a turn for the worse.

Owen goes to the spirit world to find Lola; Chief has a terrifying encounter in the maternity ward; several patients in costumes arrive on Halloween.

Blake's brother shows up at the hospital, and he needs something. Owen thinks something is suspicious about Rideworld.

Two men (Ernie Hudson and Mark L. Young) are impaled by a pole, forcing the doctors to choose who should live; Lola treats 'Star Trek' fans (Adam Scott and Clark Duke); and insult comic Jeffrey Ross comes to the hospital with an emergency.

A documentary about the cancellation of Children's Hospital.

Owen treats a boy with a knife in his chest; Glenn is pressured to squash his cure for cancer; and a telepath is admitted to the hospital.

A heat wave and subsequent power outage cause chaos at the hospital: Blake is violated in a closet and Dori comes up with a new way to make eggs.

Budget problems force a dilemma for Sy, get rid of the coffeemaker which made him popular, or fire a doctor?

Chief's daughter (Lizzy Caplan) visits the hospital; the doctors have trouble determining a patient's gender.

A senator (Ed Begley Jr.) visits the hospital; Owen struggles to treat a boy who beats him; and Sy confronts his demons.

In a special live episode, a visiting Sultan needs emergency surgery; Blake faces a crucial decision about his clown make-up; Glenn cuts off his finger for Valerie. A surprise ending reveals the shocking the truth about one of the doctors, shattering everyone's perceptions.