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At the 2012 Nantucket Film Festival, Ben Stiller, Chris Rock and Jim Carrey were the featured guests at the annual All-Star Comedy Roundtable and ETonline has an exclusive sneak peek from the special, airing September 28 on EPIX as part of Comedy Unbound, a new monthly comedy showcase.

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During the conversation, moderated by Saturday Night Live performer Bill Hader, the comedians are asked if there was ever a moment when they believed their career was over.

That launches Carrey into revealing one of his biggest early career losses: The Tonight Show. Watch!