A body by the lighthouse

Private investigator Kitt Hartley and her twin sister Rebecca are preparing for a holiday in Scotland when cruise ship entertainer Errol Jackson appears at the door. Errol breaks the news that Bryce Griffin, a former smuggler and an old friend of Kitt's, has been murdered: his body found washed up by a lighthouse, bearing a gunshot wound. Kitt persuades Rebecca to cancel their trip and, together with Kitt's assistant Grace Edwards and best friend Evie Bowes, books onto the next cruise to Norway to help with the ongoing murder investigation.