Alternate History: Another alternate history - an in-universe alternate timeline from the alternate history of Bitter Seeds. In this one, Gretel makes sure the war mostly plays out like in our history.
Alternate Timeline: Gretel's plan was to create a timeline in which the Eidolons do not kill her or humanity.
Bittersweet Ending: The warlocks are dead and humanity is saved. Marsh-2 gets to live out his life with Liv and their daughter. Marsh-1 however has to go into hiding alone overseas as he's a wanted man, and Will has been murdered by Gretel.
Brought Down to Normal: Gretel, and twice to add insult to injury; once, when the interference of two timelines stops her predicting that Liv would be rescued from the bombing of Coventry, and finally when she has her wires removed by both Marshes at the end of the story.
Character Tics: Marsh1 eventually gives himself away to Will by his habit of cracking his knuckles against his jaw.
Historical In-Joke: Gretel is apparently responsible for the Germans' slow response to the Dunkirk evacuation, and for otherwise making sure the Second World War actually happens in the way we remember it happening.
Kick the Son of a Bitch: Gretel's exile; the island is too windswept to allow wildflowers to grow (Gretel's hobby), and the last words of both Marshes are to inform Gretel that her brother Klaus is dead.
Nice Job Breaking It, Hero: Marsh1 misses a chance to contact Will because he turns up at the police station in response to a call that his billfold has been stolen, tells the police it must be a practical joke (as he still has his 1940's billfold), then leaves without even looking at the mysterious stranger who was caught with it. His Milkweed boss tears strips off him for this when it's later assumed that Marsh1 is a German spy. Marsh1 later sleeps in, missing his second and last chance to intercept Will before he recruits the warlocks.
Time Travelers Are Spies: Marsh1 ends up in wartime London with another man's wallet and no period currency. Naturally, he's suspected of being a German spy.
Trust Password: Needed to enter Milkweed. Fortunately for Marsh1, they're the same as in his timeline.
The Uriah Gambit: Marsh1 steals the blood samples of the warlocks and puts it in the box uses for the teleportation, so they'll be unexpectedly transported to the war zone where he can more easily arrange their demise.