John Mulaney returns to his Chicago high school with David Letterman as they candidly discuss addiction, fatherhood and the state of stand-up comedy.

A chaotic intervention. An action-packed stay in rehab. After a weird couple of years, John Mulaney comes out swinging in his return to the stage.

In this comedy special, Jon Stewart, John Mulaney, Chelsea Handler and Dave Chappelle honor George Carlin, Joan Rivers, Robin Williams and Richard Pryor.