The Secret Lake

When Stella and her younger brother, Tom, move to their new London home, they become mystified by the disappearances of Harry, their elderly neighbor's small dog. Where does he go? And why does he keep reappearing wet-through? Their quest to solve the riddle over the summer holidays leads to a boat buried under a grassy mound, and a tunnel that takes them to a secret lake. Who is the boy rowing towards them who looks so terrified? And whose are those children’s voices carried on the wind from beyond the woods?