This is one of those books that I should have reviewed immediately, because the plot is big and twisty and hard to hold on to. Unfortunately I was too tired to review it immediately (I finished it rather late in the evening) and I've since read a couple of other things. So here is my best attempt to recall what I thought about it.
The Great Game is the third in Tidhar's Bookman series, following The Bookman and Camera Obscura. This is a steampunk series set in an alternate world in which Amerigo Vespucci landed on an island in the Caribbean and woke the alien lizard men who who hibernating there. The lizards responded by taking over England and forming the British Empire. The French responded by having a revolution against the lizards and setting up their own government which is run by humans and artificial intelligences.
In The Great Game, we return to England, where we meet Smith, a retired spy and assassin who has been put away in the village of St. Mary Mead to keep him out of trouble. There we meet an assortment of other retired spies, including a harmless-looking old lady named M. Details like that make me very happy. Anyway, Smith is recalled to active duty when the head of intelligence, Mycroft Holmes, is murdered. Mycroft wanted Smith to investigate his murder, and so he does.
Things in Smith's life quickly become very interesting, as people keep appearing and trying to kidnap or kill him. Fortunately he is a wily old killer, and seemingly remarkably fit for someone who is repeatedly described as being old. At the same time we are following the adventures of another of Mycroft's agents, Lucy Westerna, who has been tasked with collecting Abraham Stoker upon his return from Transylvania and learning what he has to tell her. We also follow a young Harry Houdini, who works both for the Vespuccian government of North America and the mysterious Bookman. And there seems to be an alien killer on the loose.
This is a wild and imaginative adventure through London and Paris as Tidhar loots both history and literature for a diverse cast of characters to weave together in a very satisfyingly wild universe. We have fight scenes galore, and murders, and an alien invasion, and I just thoroughly enjoyed it. The only real problem I had was keeping track of the overarching plotline that holds the books together -- I have read these as they came out, with lengthy gaps in between, and I didn't always remember the events of the earlier books well enough to recall who all the players are. I think I'm going to have to go back and re-read Camera Obscura to remind me of what happened before. That said, there is plenty of stuff going on to keep a reader thoroughly entertained even if they don't fully understand the alien politics behind the story. I certainly had a blast reading it, and this is not just another regurgitated subgenre work significantly similar to all the others of its kind (unlike the urban fantasy novel I read after this book). It's incredibly imaginative and not at all predictable, and I really enjoyed it.