The Arthur MacArthur Mysteries Books in Order

The Arthur MacArthur books are Andrew Cunningham's middle-grade mysteries, written under the name A.R. Cunningham, and they have a different rhythm from his adult thrillers. The main detective is Arthur, usually called Artie, a twelve-year-old who has strong instincts, shaky judgment, and a real gift for getting himself into situations that sensible people would avoid. That is the engine of the series.

Artie does not work alone. His two best friends, Jenny Adams and Sam Franklin, give the books their balance. Jenny is sharp, practical, and usually the first to notice when Artie is about to do something reckless. Sam is less interested in mysteries but loyal when it counts, which is often. The friendship among the three is a big part of the fun. They tease each other, argue, and keep moving anyway, which makes the cases feel lively instead of solemn.

The mysteries themselves are classic kid-sleuth material in the best way. A burglar turns up in town. A supposedly ghostly antique car keeps being spotted years after it was stolen. A chemical company may be polluting the river. A plane crash leads to a coded message and a bigger theft ring. A county fair robbery puts suspicion on a singer Artie admires. Each book gives young readers a concrete puzzle and plenty of momentum without leaning too hard into darkness.

Plainville, the series setting, feels like the kind of town where rumors spread fast and strange events travel even faster. That matters because Artie is always half investigator and half local nuisance. Adults do not always take him seriously, which is part of the joke, but he notices things they miss. The books get a lot of mileage out of that tension between what kids see and what grown-ups overlook.

They are funny on purpose.

That is worth saying because the humor is not just extra decoration. Cunningham uses it to keep the danger light enough for younger readers while still letting the stakes feel real. There are crooks, missing teachers, false accusations, and risky chases, but there is also plenty of banter, awkward planning, and the sense that the kids are having an adventure even when they are scared.

If you are looking for approachable mysteries for confident younger readers, this series fits nicely. The books move quickly, the clues are easy to follow without feeling simplistic, and Artie is the kind of lead character who is fun to spend time with because he is capable, impulsive, and very sure he can solve the case, even when the evidence says otherwise.