Gordian protocol

"Doctor Benjamin Schroder was a history teacher until a psychotic episode turned his world upside down. Benjamin now had memories, not just of his own life, but of an entire ghastly world where millions of civilians had been systematically slaughtered in 'extermination camps,' there is still a Soviet Union, the Korean Peninsula is divided, thousands of nuclear warheads spread their threat across Earth and the Middle East was a festering sore of bloodshed,...

"The fates of universes aren't the only things time travel can impact. Sometimes the effect is a lot more mundane and closer to home. And when that happens, it's up to the cops of Themis Division to make time turn out right. It was supposed to be a routine trip for the members of the Gordian Division, both human and AI: fly out to Saturn, inspect the construction of their latest time machines, then fly back. But when the division's top scientist and...