The valkyrie protocol
(Book)

"Agent Raibert Kaminski and the crew of the Transtemporal Vehicle Kleio have made a shocking discovery out in the unknown reaches of the multiverse. They've stumbled across a temporal implosion that has claimed two whole universes, and neither Raibert nor his crew can figure out what caused this calamity other than it had something to do with reckless time travel. The Kleio speeds back to their home universe of SysGov with this dire report, but an audacious plan is put into effect before they arrive. Old colleagues of Raibert's from the Antiquities Rescue Trust, together with a version of Samuel Pepys transplanted from the 17th century into the 30th, have proposed an expedition into the past. Their goal? To branch the timeline by preventing the Plague of Justinian, one of the worst pandemics in human history. Meanwhile, SysGov's multiverse neighbor, the xenophobic Admin, is stirring. While their ambassadors put on a friendly show, the Admin is amassing a fleet of advanced, heavily armed time machines with SysGov firmly in the crosshairs. Time is running out for Raibert and his team. But the crew of the Kleio won't go down without a fight, no matter where - or when - the threat to their home comes from."--Provided by publisher.