Phil doesn't have a best friend in his life. That is, until Dan turns up at his school. They become close and Phil finds out that Dan has a twin brother, but hates to talk about him. It's not until Phil comes over to Dan's house that he finds out why.

Phil is an ordinary guy with an ordinary life. Nothing very special about him, he's just normal. But it all changes when, on the weirdest day of his life, he meets the very quiet and recluse, Dan Howell. He's different. Phil doesn't usually do different, but something about Dan makes him want to try it. But when he's pulled into a world he didn't even know existed, he doesn't know if his choice was such a smart one. Because, there's a reason Dan is different. And it might not be so good.