Maryellen takes a break from practicing for the big "Rock Around the Clock" holiday dance to go to the beach with her friend Davy. While playing in the waves, they find a barnacle-encrusted ring buried in the sand. They imagine that it's lost treasure from a sunken ship. But why do other people seem desperate to get the ring? Includes an essay about real-life treasure hunters in the 1950s, who explored wrecks of Spanish and French ships off the coast of Florida.