Ten Second Staircase Bryant & May Series, Book 4.

It's a crime tailor-made for the Peculiar Crimes Unit: a controversial artist is murdered and displayed as part of her own outrageous installation. No suspects, no motive, no evidence--it's business as usual for the Unit's cantankerous founding partners, Arthur Bryant and John May. But this time they have an eyewitness. According to twelve-year-old Luke Tripp, the killer was a cape-clad highwayman atop a black stallion. As implausible as the bo...