Quebec City, 1956. The fates of Nelly Maloye, a beginning private detective, and Simon Picard, a research assistant in science, accidentally cross each other. Supported by an ambitious patron, Maloye, intuitive and chaotic, and Picard, methodical and obsessive, embark on an adventure to prove the existence of the Yeti. To get there, Simon relies on an explorer's diary to take them to the mythical creature's lair. Accompanied by Tensing, a young Sherpa guide, and Jasmin, a talkative Monk, they face many dangers in the heart of the Himalayas.