On board the moletrain Medes, Sham Yes ap Soorap watches in awe as he witnesses his first moldywarpe hunt: the giant mole bursting from the earth, the harpoonists targeting their prey, the battle resulting in one's death & the other's glory. Spectacular as it is, Sham can't shake the sense that there is more to life than the endless rails of the railsea--even if his captain thinks only of hunting the ivory-colored mole that took her arm years ago. But when they come across a wrecked train, Sham finds something--a series of pictures hinting at something, somewhere, that should be impossible--that leads to considerably more than he'd bargained for. Soon he's hunted on all sides, by pirates, trainsfolk, monsters & salvage-scrabblers. & it might not be just Sham's life that's about to change. It could be the whole of the railsea.