Mister Jinx has found a way of speeding up human metabolism thirty-fold. This means that whoever makes use of his method spends (apparently) thirty days in the space of only twenty-four hours. His wealthy clients can therefore waste no more than just one day of their extremely valuable time in order to have a whole month all to themselves. But the method often goes wrong, degenerating into death from self-combustion. Martin Mystère looks into the affair on behalf of Inspector Travis but is discovered and put in prison by the Mephistophelean scientist.