Two men, the American Emmet Carlton and the French Franz Dubois, claim to be the bravest man alive. They meet in Paris for a decisive battle. Each opponent starts pulling pranks to scare the other out of his wits – and thus be announced the winner. In the end they engage in a pistol duel and perish both.
Sam Larkin poisons professor Hartford and hooks the scientist’s brain to a mechanical thinking machine to calculate gambling odds. Larkin wins at roulette and boxing bets. When he takes every last penny to the horse races, he is taught a lesson: Hartford is still alive and rigged all his winnings to ruin his criminal assistant.