Sylvia McNicoll from Dundurn. It's a fun and very well written chapter book for middle readers with an appealing protagonist, Stephen Noble and his sidekick, Renée Kobai.
I really loved that this book gently showed the main character coping and mastering life skills whilst dealing with OCD in a positive manner. He's very intelligent, careful, and honest but not an unbelievable paragon (at one point early on in the book, he's contemplating as only a 12 year old boy can, the social costs of having a friend who's a girl). He's a very likeable kid and I liked that he's not too perfect.
The plotting is steady and comfortably tense without tipping over into scary. When art goes missing around town, Renée's brother Attila gets the blame. Renée is sure that the only way to clear Attila's name is to solve the mystery themselves in between homework, school and their dog-walking job.
The book has 217 pages and would be appropriate for more advanced middle grade readers (there's very little interior art and a fairly complex plot with several story lines).
The cover and chapter heading art are appealingly naive and colorful.
I enjoyed the book very much, especially for showing the normalcy of real life for many people living and coping with OCD and other challenges.
Disclosure: I received an ARC at no cost from the author/publisher.