Percival discovers for the first time the outside world. Everything is new, everything is exciting, his heart trembles at the call of adventure. Alas, the sacred Knights of Camelot attack him without any pity because, according to them, he would be one of the Four Knights of the Apocalypse destined to destroy the world! Yet, the young boy does not stop in such a good way. He wants to find his father, guilty of having murdered his grandfather, and thus discover the truth. He is accompanied by Donnie, a traveling artist, and Sin, a fox who speaks. It is a long journey that begins for the three companions...