London & Scottish bank officer Mr. Shaw is scheduled to ride the maiden voyage of the Queen Mary to transfer $1 million in Liberty Bonds to the banks branch in America. But when Mr. Shaw is first almost run down in the street, and then poisoned, the assistant bank manager must take the bonds instead. The bank hires Poirot to accompany the bonds, so he and Mr. Hastings are able to ride the maiden voyage of the Queen Mary, much to Hastings delight. But when the bonds are stolen, suspicion falls on the assistant manager who has a history of large gambling debts.