In 1959, a group of like-minded Chicagoans joined forces to open a hip new venue dedicated to coffee, cigarettes, conversation, and comedy. The result, a nightly cabaret featuring a troupe of inventive young actors skewering everything from politics to popular culture in witty, rapid-fire, improvised scenes, not only made delighted audiences laugh–it made history.

Copping its iconic name from a New York journalist’s disparaging remark, Chicago’s Second City theater brashly defied the role of runner-up and single-handedly made the Windy City North America’s cradle of comedic brilliance from which generations of household names would spring. Now, in The Second City Unscripted, a Who’s Who of the celebrated comedy camp’s alumni–including Alan Arkin, David Steinberg, Harold Ramis, Dan Aykroyd, Eugene Levy, Amy Sedaris, and Stephen Colbert–tell it like it was in the house that hilarity built.

Here are candid tales of John Belushi’s raw ambition and chemical experimentation, Bill Murray’s heckler-pummeling and lady-killing, superstar Mel Gibson’s roof-raising appearance in Braveheart regalia, and legendary director Del Close’s shuttling between the comedic asylum he ruled over and the real one he rehabbed in.

In this unvarnished, unexpurgated, and unprecedented account, what happened onstage, backstage, and offstage at Second City isn’t staying there anymore. From the smash hits and near misses to the love affairs and the bitter feuds, from the showbiz politics and pitfalls to the inspired tomfoolery and heartbreaking tragedy, The Second City Unscripted is part memoir of a cherished era, part time capsule from a comedic renaissance, and part valentine to the exquisite art of being funny. It captures like never before the history of the men and women who caught lightning–and laughter–in a bottle.