Mesklin was a living nightmare for any human explorer: a vast disc-shaped planet with a crushing gravity up to 700 times greater than Earth's. It was a world so cold that its oceans were liquid methane and its snows were frozen ammonia. Yet the planet held secrets of unimaginable value to mankind, mysteries which could only be unlocked with the help of the Mesklin-ites, tiny creatures bizarrely adapted to their surroundings.
But it was only at the end of their appalling journey that the resourceful Mesklinite captain laid down his side of an extraordinary bargain.