Billy removes the kidney of a 9-year-old girl with an extensive medical history, and discovers signs that she's being abused. He suspects the girl's mother may be intentionally harming her daughter to grab attention. Aaron grapples with himself when he loses a patient while performing a simple procedure. Kate can't break away from the hospital to attend her daughter's school carnival. Jack gets caught in a sting at Bart's bar, prompting Phillip to insist that Jack enroll in Gamblers Anonymous.