Victor Karras has been at the helm of Karras Games for over 50 years, transforming the family run business which create beautifully handmade board games. Since the Karras family have made their fortune in games, Victor's pregnant wife, Eleanor, decided that to celebrate her husband's 70th birthday, it only seemed fitting to build such a celebration around a game and so arranged a murder mystery weekend. Gathering at Hulton Manor, a sprawling edifice on its own island, a storm rages outside adding to the immersive experience of the fictional murder playing out in front of them, until Victor tumbles down the stairs, and is impaled by a life-size Egyptian figure, killing him for real.

As Barnaby and Winter arrive to investigate, Fleur informs them that Victor was not killed when impaled by the Anubis but was dead before he hit the ground; he was poisoned with cyanide. With this, the team reason that it was likely administered in something he ate or drank in the 30 minutes before his death, giving them their window. As Fleur returns to the mainland with Victor's body, the violent storm washes away the chain ferry, the only means of transportation off the island, marooning Barnaby, Winter, the remaining family, and most importantly the killer.

With no way off the island and no way of knowing when the storm will subside, Barnaby and Winter gather the group and declare this does not mean that the investigation will cease. Interviewing the group reveals several rivalries and potential motives. Karras Games are struggling, and Victor's greedy daughter Danni was desperate for her father to step down, while Victor had also recently fired his accountant brother-in-law, Paul. Is this about power? Or revenge? With a seemingly endless number of motives and family feuds, the phone lines go down, and with little signal, Barnaby and Winter find their usual methods of detection are no longer at their disposal. The duo must work to puzzle this case out on their own like never before.