But Joe finds himself thrown in at the deep end when a man known as Ralph Holmes goes missing on the outskirts of Carlisle. Police are refusing to investigate, as his disappearance seems voluntary, but his niece, Carly Lewis, is determined to find out what really happened.
As Kitt, Grace and Joe begin to investigate, they deduce there might be more to this disappearance than meets the eye. Drawn into a web of international conspiracies and possible murder, they need to find out who Ralph Holmes really was - and who he was working for. In their most dangerous case yet, the team are in a race against the clock to uncover the truth, before anyone else gets hurt . . .