Bath Day with a View of the Abyss

After the conspiracy was uncovered in the "Suicide Club," the main hero becomes involved in investigating other crimes. The novella "A Bath Day with a View of the Abyss" tells of a mysterious death of the owner of a mountain hotel, who poisoned himself in the bath with nitrous oxide. The police and the insurance company are at a loss—was his death a natural consequence of withdrawal syndrome, or was it a carefully planned murder?