Even for a master, time travel is tricky business. But that didn’t stop legendary sci-fi and horror writer Stephen King from taking it on.

His new book, 11/22/63, riffs on an old trope: If you could go back in time and stop a horrible event, would you? Could you? And what would happen if you did?

In this case, the event is the assassination of John F. Kennedy. King’s main character finds a way to travel back in time, and that’s pretty much the last moment in the book where anything goes as planned.

King talked to story editor Sarah Fallon for a Q&A in the November issue of Wired. This episode of Storyboard is their complete conversation. King talked about the rules for narrative, the rules for time travel and changing history, and about his own rules for writing.

Warning: This episodes contains some spoilers for King’s new book. And you can’t listen, and then go back in time and stop yourself from listening. Or maybe you can, and already will have done so. How would we know?