Paul pays a visit to his aunt to check out her health. She sees right through his motives and assures him she'll live several more years. Paul feigns a fainting spell in her parlor and the cook convinces Rosalie to let him stay there the night. Paul makes himself at home in her house from then on, dining with her at mealtime and schmoozing her, all while Henri grows more desperate for funds. After Henri attempts to burglarize her house, Paul suggests that they take a different line of action and murder the old woman. Henri resists, but Paul convinces him to grind up glass to put in her soufflé, which is served without fail every other evening. Henri helps grind the glass into tiny bits, scared to death of what he's doing. Paul nonchalantly takes it and gets the old lady drunk off of wine, thereby inducing her to pass out before dinner, which he assures her she won't want to miss: soufflé glace. Henri waits anxiously at the café for news of the deed being done, and at last he's called in for a phone call.
Henri rushes over to his aunt's home and discovers that Paul had indeed mixed the glass into the egg mixture for the soufflé, but that Rosalie had broken her pattern for the first time and had fish instead. The next morning, the cook made omelets for Paul, thereby killing him with his own mixture.