This mystery for fifth to seventh graders revolves around the disappearance of Salim, a thirteen year old visiting his cousins for a few days before catching the airplane for a move to New York. At Salim's suggestion, they go to the London Eye where a stranger offers them one ticket. Since his cousins have already ridden the Eye, Salim takes the ticket and goes on alone, but at the end of the ride, he's disappeared! The mystery is finally solved by Ted, the narrator of the story, who says that his "brain runs on a different operating system from other people's" Other than the protagonist in A Curious Incident of a Dog in the Night-time, it's one of the best portrayals of a boy with Asperger's syndrome that I've read. He's totally engaging.