When photographer Davey Cartwright accepts an invitation to tender for a honeymoon cruise he is as unaware it is the first step in a planned revenge as he is of his ex-porn-star wife’s past.

Similarly, Ed Hetherington’s self-congratulation at exchanging dodgy US dollars for a share in ScotCruise wanes when he realises others are reaping financial benefits.

On board, not all honeymooners are what they seem. A journalist fears brides are being murdered to order and co-opts a colleague to masquerade as husband. An art thief’s last-minute choice of assistant renders him vulnerable, and he is as unaware of DI Luke Darbyshere’s intent to arrest him as Luke is of the presence of a one-time friend whose wife he immediately plots to bed.

As they sail from Leith to Lerwick one bride disappears. A second suffers a fatal accident. In Shetland, death comes closer still and the week culminates in a pursuit through Edinburgh’s Waverley station.