Economic spy Eliza Roth-Schild has fled to New York, leaving her loyal chauffeur, taxi driver, and amateur detective Mr. Wälti feeling down. However, he unexpectedly stumbles upon a rather peculiar case: someone is stealing large quantities of toilet paper from the upscale hotel Castello Cavallo, but not just any toilet paper—it's the luxurious kind with a gold trim. Wälti is tasked with finding the thief. As a taxi driver, he serves as a confessor, life coach, and comforter all in one, remaining silent and discreet. He receives help with this seemingly ridiculous toilet paper assignment from the new employee at the taxi dispatch. Evita Mosimann is young, quirky, cheeky, tech-savvy, has a mysterious past, and some puzzling habits. Together, Wälti and Evita search for the thief and uncover a conspiracy that could change the course of world history.