For eleven-year-old budding detective Alice Clark, summers in Trevellen used to mean roaming the beaches and rock pools, collecting shells with her sister, Poppy.

But this year is different. A year after Poppy’s death, Alice returns alone – determined to build a shell memorial in her honour, and desperate to ensure her sister is never, ever forgotten.

Forbidden from visiting the beach by herself, Alice reluctantly strikes a deal with Jasper – the annoying boy who’s just moved in next door.

But the arrangement quickly becomes more complicated than she expects.

Drawn into the heart of a sinister World War II mystery, Alice and Jasper find themselves in real danger, unearth a shocking family secret, and risk losing the one thing Alice came back to Trevellen to protect.

An award-winning novel set in Cornwall, UK.