See my review of this book, and many more, at Tales from the Great East Road.
(Spoilers for the first two books in the series.)
To be given the chance to undo the mistakes of his past, to not only change the fate of his family but also save the world, Raybould Marsh has agreed to trust his most despised enemy. Gretel is one of the few living genetic experiments created by the mad Dr Von Westarp, who were used as soldiers during the Second World War. She can see the future, and has used her powers to kill Marsh’s infant daughter once already. But the only wait to save his baby, and everyone else, is to trust Gretel. As the Eidolons – a race of god-like beings who abhor humans – destroy the world Gretel is able to send Marsh back in time from 1963 to 1940 in order to save this time line from destruction and redeem himself.
Necessary Evil is a very bittersweet book. After seeing Marsh become a shadow of the man he used to be in the last book, The Coldest War, he is given a chance to change history – but for a different version of himself. He gets to see his wife, when she still loved him, and his baby daughter, who has been dead for nearly twenty years, but can’t reveal who he truly is. Marsh’s pain and loneliness is visible throughout the novel, and heart-wrenching to read.
The comparisons between Old Marsh and Young Marsh is interesting to read. Both are obviously stubborn and determined to protect their family, but Old Marsh has become better at scheming and manipulating people: more willing to do the “necessary evil” in order to reach his goals. His loneliness has hardened him, and the possibility of saving his child has made him desperate. Yet, despite these faults, Old Marsh is a constantly sympathetic character.
The few insights we get into Gretel’s mind are fascinating, in a very disturbing way. She has been described as “evil” constantly throughout the series, and these chapters certainly show she is unstable and obsessive, willing to kill anyone who gets in her way. No-one is safe, and a few key characters are killed in a fairly gruesome way.
Ultimately, this is a satisfying and emotional ending to a great series.