I went into reading Siobhan Dowd's The London Eye Mystery with mixed prejudgements. On the one hand, I planned to love it as I enjoy any book set in contemporary England because I just adore reading about people eating crisps and puddings, wearing trainers, and going "to hospital." On the other hand, I had decided that it might just be The Curious Incident of the Dog in the Nighttime Light. It does bear some strong similarities to Mark Haddon's novel as both stories have male protagonists on the autistic spectrum solving mysteries, but the books are very different and worth reading.
The London Eye Mystery has been written for a younger audience. I would say it is ideal for fifth through ninth grade readers. It tells the story of twelve year old Ted who has, I believe, Asperger's Syndrome, and his older sister Kat who decide to solve the mystery of their missing cousin Salim. All three had been on a queue (another word which keeps me reading British novels) to ride the London Eye. A stranger offers Salim a ticket to ride, and he goes up on the sealed pod but does not come out when the ride is over. Ted' brain which "works on a different operating system" than other people's is ideal for solving the mystery. It is a tightly constructed mystery too, making for a very satisfying read.