Urchin Beach isn’t the sort of place where bad things happen. The little seaside town is too lucky for that. But then one day, a thief steals something precious—the town’s dragonfly staff, which is the source of all its good fortune and the most important part of the upcoming Dragonfly Day Festival.

Amelia MacGuffin is no detective. She’s eleven, quiet, and unlike her four younger siblings, she has no special talents. But Amelia loves her town. Her family has lived there forever. Her parents run the Pacific General Store, and she and her best friends, Birdie and Delphine, are about to start middle school. If Amelia doesn’t find the staff, the Dragonfly Day Festival will be canceled.

The town needs that tourist money to survive. Unless she cracks the case, Amelia’s family will lose everything—including the adorable stray dog they’ve fallen in love with. She only has seven days to solve Urchin Beach’s crime of the century. It’s not a lot of time, but Amelia has her list of suspects. It might be the new kids next door. Or the grumpy mystery writer who lives in the town’s creepiest mansion. Or perhaps even someone closer to home.

Amelia wants to save the town. She wants to save the dog. She wants both, so much.

But first, she has to catch a thief.