This is a weird novel. It has one major MacGuffin which requires extra suspension of disbelief, because it's one of the most annoying scientific blunders in popular sci-fi, covered over with some quasi-magic mumbo jumbo. It's absolutely central to the plot, but a little hard to swallow. However, the mumbo jumbo is handled well enough that I was able to get past it and follow the story. Really, the hardest thing about enjoying the story is that the central character is a nasty sort of person, and a lot of the story takes place inside his mind, which (although it's handled fairly well) isn't a very pleasant place. There is definite character development, but the characters are hard enough to identify with that I found it hard to really care, even as our hero clearly comes out a different and better person than he went in. There's a rip-roaring adventure story woven through the psychological stuff, which is pretty good, and there's some interesting societal speculation. I was definitely not bored; it's an intriguing book, but I only partially liked it. 7 out of 10.
One note: this book is full of Spanish profanity, or at least a lot of words that I assume from context are not usable in polite company.
**** PLOT SUMMARY -- MASSIVE SPOILERS ****
(Note: I'm blowing off the diacritical marks on names here so that I can actually type this.) Ramon Espejo is a low-life on Sao Paulo, a human colony brought there by the aliens who have starships. He makes a meager living as a prospector and the rest of the time sponges off his girlfriend Elena, with whom he has an abusive, violent relationship, but despite regular fights, they more or less stay together. He gets drunk in a bar and kills a human visitor from off-planet, who turns out to be an ambassador. He skips town into the wilderness, figuring that even though they probably know he did it, if they can't find him for a couple of months, they will probably have to hang someone else for the crime. So he flies north beyond the human-inhabited part of the planet and starts exploring. An exploratory blast into an anomalous looking mountain reveals a hidden alien base. An alien comes out shooting, injures Ramon, and blows up his flying van, but Ramon escapes.
Then we switch viewpoints to a Ramon who wakes up in a vat. The original Ramon had a finger torn off in the attack, and the aliens cloned a new one from it. Through some mystical process called "flow", they establish enough connection between the original and the clone that the clone has almost complete memories and believes that it is Ramon. Then the aliens plug a living leash called a sahael into his neck, and force him to track the original one. The clone (who is the viewpoint character for the whole book; the initial action actually took place in flashback) is angry at being enslaved and tries to resist, but the sahael can inflict irresistible pain, and he's soon tracking. The original is very resourceful, though; he plants a bomb which seriously wounds the alien minder, Maneck. It also damanges the sahael in such a way that the clone Ramon receives some of Maneck's memories. Maneck's species was almost wiped out by invading aliens; his hive and a few others are hiding in various systems. And the aliens who did the original wiping out and are still pursuing are the Silver Enye, the aliens who planted the colony. The clone develops considerable sympathy with Maneck's cause. The original, despite the fact that he's fleeing across uncharted jungle with only one hand, is not out of tricks; he lays a string of dead animals in the path that attract a chupacabra -- a dangerous predator somewhere between a tiger and a T. rex. Maneck and the chupacabra fight; Maneck seems to be losing when he retracts the sahael from the clone to use it to fight. The clone runs and catches up with the original, but believing that the original would not accept him if he told the truth, lies about who he is. Together, they build a raft. An unexpected waterfall makes the journey exciting. Eventually, the original stops believing the clone's story, and it progresses to a fight; the clone wins the fight and kills the original, but he's fairly seriously wounded and slips into delirious dreams as the raft carries him down the now-placid river to civilization. He seems to be home free, but the Silver Enye discover the garment the clone was given aboard their ship, which is clearly an artifact of Maneck's species. The clone manages to pull off a lie, aided at the end by Elena, who unexpectedly backs up his lies by claiming that he'd had the robe for years. A glance and a nod convey to clone-Ramon that the governor's secretary -- the woman Ramon originally killed the ambassador over, because the ambassador was planning to rape her just to prove that he had so much power that he could, and Ramon, a bystander, intervened -- got to Elena and told her what lies to tell to save Ramon.
At the end of the book, clone-Ramon has managed to wheedle a barely-functioning van to get back into the wilderness. He has a plan to get the aliens to tell him where the valuable minerals are in the north; he will use the wealth to establish claims on the areas where the aliens are hiding to keep other prospectors from finding them, and in the process become very wealthy. And if he and Elena manage to continue their respective journeys from crazy barely-above-animals to mentally functional people, they might even live happily ever after.