Jen Dunne is forty-two and getting married for the second time, but that doesn't mean she can't go all out for her bachelorette weekend. She's taking her closest friends to the kind of place that has a years-long waiting list for a booking: three days of super-exclusive luxury accommodation on a remote Scottish island. So excited by the complicated means of transport required to get to the island, no one gives much thought to the implications for getting off again, especially if the weather should turn. But why would they? They're in for a time they will never forget. Just not for the reasons they imagine.

When one of the party mysteriously goes missing on the first night, Jen realizes she has made a terrible mistake: she has trapped this disparate group of women together until the helicopter returns at then end of the weekend, and each woman has a secret...

Get ready for a closed circle mystery like no other. One that asks: how well do you really know anybody, even your oldest acquaintance? And what if your best friend is really your worst enemy?