Mandy McMillian

Claire delicately helps Luke cope with the fact that his friend and their old neighbor, Walt, has passed. Phil takes Alex for some father-daughter bonding time, and Haley throws an unauthorized party. Meanwhile, Jay and Gloria go over to Mitch and Cam's to have dinner with Cam's father, Merle, who is in town visiting -- and awkwardness and tension seem to be the rule of the night.

Burger-mad Marshall meets Regis Philbin while on a quest to find the restaurant where he had his very first New York burger.

Luke gives April a birthday party at the diner; a stunt with the Life and Death Brigade seriously injures Logan.

The team pursues a copycat serial killer who is recreating the techniques used by past famous murderers.

The doctors reminisce during a celebration at Addison's house; Sheldon counsels a suicidal patient who makes a shocking confession.

While investigating a building collapse, Lightman discovers a massive cover-up; a billionaire asks the team to determine if his girlfriend loves him for the right reasons.