Double Crossed (Invader Zim)
Book Cover by User Moxuu_
After realizing that they're bored without bashing each other's antics, Dib and Zim befriend each other. Soon after, Zim finds himself on an autopsy table, and believes Dib to be the culprit. Thinking quickly, he travels back in time to when he befriends Dib, intending to stop the event from taking place. But in the process, he finds out that Dib wasn't planning anything of the sorts. Now without a disguise, Zim must team up with his greatest enemy (and at the same time his only friend) to find who else in this world of idiots would know Zim's true identity.
Side note, this book does contain ZaDR (Zim and Dib Relationship) so if you don't like ZaDR, I'm telling you now that you can leave.
As well, this book is a work of fiction-within-fiction, meaning that it is NOT canon to the show. It takes place after the events of Mopiness of Doom (an unaired episode, which you can watch on youtube in the form of either an animation project or an official script reading, neither of which are mine.) and doesn't fully follow the canonicity of future (unaired) episodes. If you haven't seen Mopiness of Doom, some elements of the story may not make sense.