Djuna and his dog Champ go to Stony Harbor to spend what he thinks will be a quiet and uneventful holiday in a seaside village. But little does Djuna know what is in store!

First he meets Billy Reckless and his dog Alberto. Then there's the mystery which enshrouds Djuna's Aunt Patty. Things begin to happen! Djuna has a grand time with his newfound friend, lobstering, sailing, and exploring, until Aunt Patty's motorboat, the Patagonia, mysteriously disappears.

Ellery Queen Jr. has created a likeable character in Djuna the junior sleuth, not forgetting, of course, his black Scotty, Champ. Their adventures are told in clear, bright language, and they hold interest from start to finish.