Tor, 2013, 384 pages
May 12, 1940, Westminster, London, England: the early days of World War II.
Raybould Marsh, one of "our" Britain's best spies, has travelled to another Earth in a desperate attempt to save at least one timeline from the Cthulhu-like monsters who have been observing our species from space and have already destroyed Marsh's timeline. In order to accomplish this, he must remove all traces of the supermen that were created by the Nazi war machine and caused the specters from outer space to notice our planet in the first place.
His biggest challenge is the mad seer Greta, one of the most powerful of the Nazi creations, who has sent a version of herself to this timeline to thwart Marsh. Why would she stand in his way? Because she has seen that in all the timelines she dies and she is determined to stop that from happening, even if it means destroying most of humanity in the process. And Marsh is the only man who can stop her.
Necessary Evil is the stunning conclusion to Ian Tregillis' Milkweed series.
Necessary Evil is the third and final volume in the "Milkweed Triptych" series (I wonder if it was the author or the publisher who decided to use such a pretentious substitute for "trilogy.") Thus, this review contains GREAT BIG HONKING SPOILERS for the first two books.
Ian Tregillis's alt-history is a truly original and exciting SF series, and I'm sorry it's not gotten more attention. It might not rise to the level of true greatness, but how can you say no to a high concept premise like "Nazi supermen vs. British magic powered by Elder Gods"?
In Bitter Seeds, British secret agent Raybould Marsh and his poncy toff friend Will Beauclerk try to find a way to fight supersoldiers created by Nazi science. The solution is the top-secret Milkweed project: gathering Britain's warlocks, who can bargain with cosmic horrors called Eidolons, they use magic to destroy the Reich's armies and counter the supermen, at the cost of sacrificing their own citizens.
The second book, The Coldest War, takes place in the 1960s. The Soviet Union now has control of the Nazi supersoldier project, and the only thing keeping the Soviets from taking over the world is the Milkweed project.
Both books were strong on plot and concept, a little weak on characterization. Book two ended with the literal end of the world.
In Necessary Evil, Raybould Marsh is sent back in time thanks to Eidolon sorcery and the machinations of Gretel, the most powerful of all the original super-soldiers, with the power to see the future and, it turns out, all the many possible branches it can take, and choose between them. Gretel is basically unstoppable: she brings into the question the very existence of free will, since nothing happens that she doesn't foresee. Unfortunately, she foresaw the end of the world in every possible future, and so schemed to create a new timeline in which the Eidolons don't destroy the world and she lives.
Thus, Necessary Evil is not only an alternate history but a time travel novel. The older, scarred Raybould Marsh has to somehow manipulate his younger self and his friend Will into not using the power of the Eidolons to save Britain from the Nazi supermen. The problem with this, of course, is that saving the world might mean losing World War II. With a younger Gretel also involved, still playing her omniscient games, the plot twists through replays of events in the first book, taking them in new directions.
Like the first two books, Necessary Evil is heavy on plot and imagination, and while the characterization is still a little shallow at times, the tormented Raybould Marsh, seeing a wife that still loves his younger self, manages to elicit sympathy, while Gretel becomes, almost, human. Still batshit crazy and evil, but human. The "necessary evils" the characters are required to perform cause quite a bit of angst, but they never really search for alternatives.
Time travel is tricky to pull off; time travel combined with an all-seeing precog even trickier. How do you create surprises and avoid paradoxes? Tregillis manages to pull it off without unraveling the plot. The ending is just right: a climactic battle, a bittersweet victory, and just desserts. It's a fine ending to the trilogy.
Verdict: Necessary Evil brings the Milkweed trilogy to a finale, so definitely do not read it out of order. The ending suffers only from a bit of deja vu thanks to the events of the first book being replayed and altered, but it's a satisfying conclusion to a great series.
Also by Ian Tregillis: My reviews of Bitter Seeds and The Coldest War.
My complete list of book reviews.