While the apocalypse has been stopped and life seems to be returning to normal, Klaus is still reeling from the loss of Dave. When Dave appears, alive, in their apartment, Klaus thinks he's finally been dealt a fair hand at life. But as Dave adjusts to this new time and new place, cracks start to show in his and Klaus's relationship. And then there's the mystery of how and why he arrived in 2019 and survived his mortal wounds in the first place.
Dave Katz had never meant to be a soldier. He was never meant to die in the trenches of the A Shau Valley. But even at the untimely end, he was glad he ever enlisted to begin with.