America's favourite baby-sitters are detectives, too!
Luke Martinez, one of the BSC's newest charges, acts like he doesn't trust his sitters. He's definitely hiding something from them, and he seems afraid to let anyone discover his secret. But Mary Anne and the BSC plan to do just that. They think Luke's secret holds the answer to a mysterious fire at his house . . . and information that could help stop a mean developer from taking over Stoneybrook. Can they win Luke's trust before it's too late?