Orphan Henry's dream to see the ocean finally comes true when his Aunt Agatha plans a seaside vacation. But Henry's got more important things to do than sit on the beach & eat ice cream. He has a mystery to solve!
Henry can't sleep a wink his first night at Sibbald House because he hears moaning & groaning coming from somewhere inside the house. & when Henry discovers a hidden bedroom that makes the skin on the back of his neck prickle, he knows just who to call for help: Harvey Angell, the man with a five-hundred-kilowatt smile & Connecting Kit bulging full of curious gadgets.
The townspeople refuse to shed light on the mystery, but none of the lodgers are going to get any sleep until Henry & Harvey uncover the shocking secrets of Sibbald House.