A fatal slip on the toy car that his son had left in the bathroom, and Victor Tourterelle is dispatched straight to the other side of the mirror, to the beautiful world of chalk desert, under a sky as black as ink. No noise, not a soul. In his new state, Victor finds that he's still fully conscious, more acutely than on earth, even. But his body is only bones. Little does the dead man know that he's at the dawn of the wildest adventure of all time...

The bony masses are gripped with blind panic ever since the new arrival, renamed 'Ash Tuesday', started kicking up a fuss about his post-mortem condition. Ash Tuesday manages to escape during his transfer to Saint-Luc, the adjustment center for twisted spirits. The Militia sends out search parties all over the land to try and track down the dangerous rebel escapee. But Ash Tuesday is soon recruited by a clandestine group that entrusts him with the gargantuan task of drawing up a map of all purgatory.

Poor Ash Tuesday, in the midst of a general uprising, is still seeking his soul which is being detained by a formidable sect. His quest plunges him right to the heart of Pluto and into the eight circles of Purgatory. Will this finally put an end to his wanderings? Why does he seem to be the only one seeking redemption? Will he ever find his way out of this labyrinth?

Mr. Ash Tuesday finally comes to the end of his wanderings. Right at the heart of Pluto and the first circles of Purgatory, Ash Tuesday comes face to face with the painful incarnations of his past. Thus the postman and his companion at last discover the true nature of Purgatory. It's all a bit too much for Ash Tuesday, who ends up fleeing the scene and returning to Saint-Cecile. Back in Saint-Cecile, chaos rules following an overdose of Lethe (the river of forgetfulness) and a deluge of coffee rain. This is when a certain skeleton discovers the resurrection formula: the combination of forbidden coffee and sincere repentance. Finally Pluto will be purged of its population of tormented souls! But will they once again be tempted to return to the pleasures of the flesh? Of course they will!