Libby Hall never really wanted to be noticed. But after she saves the children in her care from a fire, she finds herself headline news. And horrified by the attention. It all reminds her of what happened nine years ago. The last time she saw her best friend alive.

Which is why the house swap is such a godsend. Libby and her husband Jamie exchange their flat in Bath for a beautiful, secluded house in Cornwall. It's a chance to heal their marriage - to stop its secrets tearing them apart.

But this stylish Cornish home isn't the getaway they'd hoped for. They make odd, even disturbing, discoveries in the house. It's so isolated-yet Libby doesn't feel entirely alone. As if she's being watched.

Is Libby being paranoid? What is her husband hiding? And, as the secrets and lies come tumbling out, is the past about to catch up with them?