If you haven't read Jason Hough's Dire Earth cycle, you should. If you have, you will be delighted to hear that his new novel, Zero World, is just as good. Completely different, but just as good.
Assassin Peter Caswell has an implant that blocks all memories of his missions. An assassin who can't remember ever killing anyone? Interesting. His new mission sends him on a recovery mission in space. When they get to the abandoned ship, they find the crew all dead, except for one who is missing. Caswell's implant kicks in, marking the beginning of the period in which he won't be able to remember anything. He then kills the rest of his crew and takes a shuttle to pursue the one missing crew member.
To his great surprise, he finds himself on a world eerily similar to Earth, a parallel world with familiar geography and whose inhabitants speak a close proximation of English, yet with many odd differences. The technology of this world is a century or two behind Caswell's Earth, and he learns that the missing crew member has been introducing technology, making her powerful and rich in this new world.
Caswell's mission takes a twist when he and Melnie, an agent who has been spying on Caswell's target, end up as an unlikely team. Just when I thought I saw where the story was going, Hough inserts a twist that changed my perspective--and Caswell's mission--completely. Then that pesky mission-forgetting implant gets in the way at just the wrong time. . . .
Hough's writing is crisp, his pace is breakneck, and the alternative world building is captivating. His Dire Earth novels are epic in scope, with a huge cast of characters. Zero World focuses on Caswell, but the scope is still enormous. The implications of all that Caswell experiences open up a new future for humanity (and, hopefully, some sequels). If you like sci-fi with lots of action, lots of cool tech and lots of parallel world speculation, Zero World is sure to satisfy.
Thanks to NetGalley and the publisher for the complimentary electronic review copy!