In the future, 30,000 years distant from our time, on the planet Icefall, in its only city of Neverness, there is the Order of Mystic Mathematicians, divided into numerous factions, and one of them is pilots. These brave people, who maintain a neural connection with their ships, travel throughout the Universe. Sometimes they enter real space, sometimes they replace it with the space of mathematical sets, which allows them to overcome enormous distances. Each time this is a terrible risk, because mathematical space is treacherous and is fraught with many threats - it has happened more than once that ships that got lost in the tree of probabilities disappeared without a trace. But countless mysteries of vast space continue to attract researchers. Find the legendary Old Earth? Unravel the secret of the mythical race that seeded the Galaxy with life and hid its collective mind in a black hole? Prove the Great Theorem, which allows you to get from one star to another in one single jump? For the young and those who are pure in spirit - nothing is impossible!