Lovejoy agrees to help Madeline Gilbert, a once famous film star fallen on hard times, to sell her valuables, but she is burgled by an armed French gang who have crossed the Channel after killing a gendarme. Lovejoy has an alibi - auctioneer Melanie Ford - but he wonders if she has been coerced into tipping off the villains. Before the gang is caught, Tinker puts himself in danger by boarding a boat belonging to Lovejoy's chief suspect, a respected army major.