Help the Viking leader, Ragnar Lodbrok, find Odin's relic before Moriarty, Sherlock's enemy, takes hold of it. Discover the history of these Vikings who came to invade the city of Nantes in the 9th century, get to know their gods and decipher their runic alphabet. The game starts when you start the chat with the chatbot. After giving him your access code, he will give you the details of your mission. You can then go on an adventure and walk the streets in search of clues. Observe your surroundings, solve puzzles, and interact with your digital companion (as well as your teammates) to complete your quest. The necessary equipment : - A charged smartphone with internet access (1 / team mandatory - 1 / player recommended) - A notebook and pencil (1 / team)