The year is 1662. Cromwell is dead, and Charles II presides over an uneasy court, where former enemies mingle and plot. With rebellion stirring in the Scottish Isles, the hard-pressed king needs men he can trust to sail north and deal with this new treachery. Matthew Quinton is one such man, but though loyal he is inexperienced; his first command was lost at sea within weeks. Now, aged twenty-two, he is determined to complete his second mission without loss of life or honour. With him goes Kit Farrell, a sailor who has promised to help Matthew master the sea. So too does Phineas Musk, an old rogue untroubled by manners or conscience, but one who would lay down his life for his master. As they sail for Scotland, Matthew must tackle the dangers of the voyage: a resentful Cornish crew, a suspicion of murder, and the growing conviction that treason lies closer to home than anyone thought.