Konets vechnosti

Eternity is an organization and a place which exists outside of time. It is staffed by humans called "Eternals" capable of traveling and entering the conventional temporal world at almost any point of their choice, apart from the far future which they cannot enter. Andrew Harlan, an expert in executing Reality Changes, realizes that he is part of a paradoxical scheme to secure the creation of Eternity by sending a young Eternal back in time with the mathematical knowledge to make it possible.