In September 1913, Mieczyslaw Wojnicz, a student suffering from tuberculosis, arrives at Wilhelm Opitz’s Guesthouse for Gentlemen, a health resort in what is now western Poland. Every day, its residents gather in the dining room to imbibe the hallucinogenic local liqueur, to obsess over money and status, and to discuss the great issues of the day: Will there be war? Monarchy or democracy? Do devils exist? Are women inherently inferior?  Meanwhile, disturbing things are beginning to happen in the...