The captain of the Newhaven to Dieppe steamer spots a small pleasure yacht lying motionless in the water, and on closer inspection, sees a body lying on the deck. When members of his crew go aboard the yacht, they find not one male corpse but two. The dead men were chairman and vice-chairman of Moxon General Securities, one of the largest financial houses in the country. Inspector Joseph French of Scotland Yard is called in. French soon discovers that Moxon's is on the brink of collapse. Moxon and Deeping seem to have been fleeing the country with their ill-gotten gains, but who killed them, and how?