Rainbow Rowell’s next book, Carry On, will not only be a spinoff of her 2013 YA novel Fangirl, but it’s also a fantasy set in the magical world of Simon Snow! Which is basically Harry Potter, but if Harry and a Draco/Snape hybrid were roommates. And fell in love. Yes.

Rowell announced the news on her Twitter last night:

My next book comes out next October, and the title is … CARRY ON. — Rainbow Rowell (@rainbowrowell) December 10, 2014

CARRY ON will be a Simon Snow story. And a Simon & Baz story. A love story. It’s my 1st fantasy & it comes out in Oct. I hope you like it! — Rainbow Rowell (@rainbowrowell) December 10, 2014

In Fangirl, college freshman Cath is famous on the Internet for her Simon Snow fanfiction—written with her twin Wren—but far less capable at interacting with people IRL. The book is interspersed with snippets of Cath and Wren’s Snowbaz fanfic while they navigate freshman year, their own baggage relating to their parents, and new love—plus, the agony of waiting for the last Simon Snow book to come out. Outside of Fangirl, Rowell has written about how important fandom is for teenagers and adults.

Clearly the world Rowell created struck a chord, because now she’s diving into her first full-fledged fantasy with Carry On (named for Cath’s much-loved fanfic, Carry On, Simon). Here’s more info about the plot, from Rowell’s Tumblr:

Simon Snow just wants to relax and savor his last year at the Watford School of Magicks, but no one will let him. His girlfriend broke up with him, his best friend is a pest, and his mentor keeps trying to hide him away in the mountains where maybe he’ll be safe. Simon can’t even enjoy the fact that his roommate and longtime nemesis is missing, because he can’t stop worrying about the evil git. Plus there are ghosts. And vampires. And actual evil things trying to shut Simon down. When you’re the most powerful magician the world has ever known, you never get to relax and savor anything. Carry On is a ghost story, a love story, a mystery and a melodrama. It has just as much kissing and talking as you’d expect from a Rainbow Rowell story—but far, far more monsters.

Rowell also hinted at more Fangirl news later in the week. A movie adaptation? Simon Snow trading cards? At this point, it’s icing on the cake.

Carry On comes out October 2015.