After an experiment into telekinesis and the power of the mind, Duncan Wemyss finds himself transported to a terrifying new world. A planet with an absolute "up" and "down", a place where lower latitudes tilt ever more wildly towards an infinite drop into the abyss of deep space. Topland, the territories around the North Pole, are the only level spaces and fiercely defended against the invaders from below. Desperate to escape their precarious existence...