Interpol are called in after a cross channel swimmer is killed moments after he completes his swim. Duval must puzzle out the man's last words and try to understand why he was killed.
A cross-channel swimmer is shot as he arrives in England, his last words hinting at some startling revelation. Duval investigates and finds the crossings being used as a cover for a drug-smuggling ring. Knowing the French end of the operation, he plays a dangerous game to provoke a reaction and expose the contact in England.