Stuart Fails to Save the Universe

Set in the future, comic book store owner Stuart Bloom is tasked with restoring reality after he breaks a device built by Sheldon and Leonard, accidentally bringing about a multiverse Armageddon. 
Stuart is aided in this quest by his girlfriend Denise, geologist friend Bert, and quantum physicist/all-around pain in the ass Barry Kripke. Along the way, they meet alternate-universe versions of characters we've come to know and love from The Big Bang Theory. As the title implies, things don't go well.