The story is set in a beautiful seaside cove in Cornwall. According to the records it was once rife with ship wreckers and smugglers. There are rumors of a secret smuggler's tunnel, but no one has ever found it. Annabelle and Harry are determined they are going to find the tunnel! During their search they discover a gold locket in a rock pool. Inside the locket is a photo of a girl and a lock of hair. When they show the locket to the lady in the cafe, she remarks, "It must have been left by the smugglers!" And so starts their most exciting adventure yet! Join Annabelle and Harry to see if they can discover the identity of the girl in the locket. Can they find the smuggler's tunnel? Find out how they use DNA to unlock questions about the past. Children reading this book will learn about DNA, cells, and forensic science. They will discover how DNA is inherited, how we can use DNA to find out where someone originates from, and to establish if they are related.