Rigby Rhymes wants one thing out of life: a grand adventure, just like the ones in her favorite books. Preferably one involving secret passageways, magic spells, and dashing, long-haired guys with swords. Unfortunately, she lives in the real world, and no wizards have stopped by to tell her she's the Chosen One. So when she kicks the bucket before even learning to drive, her dreams of adventure die with her.

But then, en route to the afterlife, an eccentric angel offers her a deal: if she agrees to enter the story-world of her favorite novel and change the plot enough to keep the brooding villain, Wick, from dying at the end, she'll get a second chance at life.

But when snoopy Wick discovers he's a fictional character and tears Rigby's copy of the book in half, he inadvertently stops time in the story-world and attracts the attention of the interdimensional Vices, a book-burning motorcycle gang of Deadly Sins obsessed with eradicating happy endings. With the unlikely help of Wick (and her goody two-shoes fictional crush, Chance Golden), Rigby must return to the real world, seek a mysterious librarian called the Bookbinder, and repair the book before the Vices destroy the story-world—and Rigby's last chance at a grand adventure—forever.