Ambitious, overcomplicated time-travel saga from the author of The Paradox Men (1984). In the future, following a nuclear war, the population of Earth is rebounding rapidly. But with much of the globe a radioactive desert, what to do with all the people? The solution: plant colonies in Earth's distant past! James Konteau, a time-travelling field agent or ""krono,"" enjoys some R & R on Deimos, when he learns psychically that a time-quake has endangered one of the colonies he set up. He alerts the Vyr Paul, a powerful overseer--but the Vyr tells Konteau that the colony is lost and that no rescue will be attempted. Konteau, disbelieving, rounds up a team anyway, including his estranged lover Helen, and travels into the past--where he saves the colony, nearly gets killed, and finds evidence of double-dealing and sabotage. Who and why? Well, Paul has ambitions to be the next Vyr Overlord; but he can succeed only by discrediting Konteau. The latter prevails--thanks to some high-powered technological help--and learns that his mysterious helpers are time-travellers from the future, come back to lend a hand in overthrowing the evil Vyrs. That's not the half of it. Complications sprout from every page; Harness sets up paradoxes and fails to resolve them; and the reunited-lovers subplot is too pat to carry much conviction. Overall: dazzling, shaky, often fascinating, irritatingly problematic.