Last summer, Alice Ogilvie's basketball-star boyfriend, Steve, dumped her. Then she disappeared for five days. Where she went and what happened to her is the biggest mystery in Castle Cove. Or at least it was. Because now, another one of Steve's girlfriends has vanished: Brooke Donovan, Alice's ex-best friend. And it doesn't look like Brooke will be coming back ...

Enter Iris Adams, Alice's tutor. Iris has her own reasons for wanting to disappear, though unlike Alice, she doesn't have the money or the means. That could be changed by the hefty reward Brooke's family is offering. The police are convinced Steve is the culprit, but Alice isn't so sure.

Luckily, Alice has exactly what they need to crack the case - the complete works of Agatha Christie. If there's anyone who can teach the girls how to solve a mystery, it's the master herself. But the town of Castle Cove holds many secrets, and Alice and Iris have no idea how much danger they're about to walk into ...