When a Russian ship docks in Whitby, Nick and Kate meet a sailor demanding political asylum and claiming he had to fight for his life to get into Britain. When he goes missing, it leads Blaketon and his men into a case that sees them forging an alliance with the Secret Service. Meanwhile, Greengrass' poaching leads him into a chance encounter with an unlikely partner in crime.

Nick and Kate's marriage is on the rocks as they continue to drift apart now that Kate has got a job in Whitby. Kate hasn't told Nick about her pregnancy, and with their marriage in crisis, she questions whether a baby is right for them, and she begins neglecting her patients. As Kate seeks comfort in Dr Radcliffe, Nick decides to take his mind off his marriage troubles by investigating a spate of roof thefts. He discovers Greengrass has been selling lead and suspects the old rogue is in league with three corrupt soldiers.