FULL DISCLOSURE: I know this author personally. Or maybe I should say I “knew” him, since we haven’t spoken in twenty-five years or more. He grew up about a block away from me, and it might be an overstatement to say we hung out together, but I definitely know him, and he knows me. There was never any doubt that he was a nice guy, and very smart, but before reading this, I didn’t know what an imagination he has! Does knowing Mike bias my review? Only in this sense: if I couldn’t give this book four or five stars, I simply wouldn’t review it. That turned out to be no problem here, since I thoroughly enjoyed my Cinco de Mayo.This is definitely science fiction of the “thought experiment” variety. Mike Martineck takes the world as we know it in present day, introduces a single new twist, and then steps back and writes about what he thinks would happen. So what’s the twist? It’s this: some sort of event occurs… perhaps supernatural, perhaps alien technology, etc, in which suddenly every human being on the planet is (apparently randomly) paired up mentally with one other person, and they suddenly share memories, knowledge, and skills. One’s paired person is called one’s “Other”. So if I had, say, Keith Richards as my Other, then suddenly, even though we've never met, in addition to my own memories, I’d have all his memories of crazy parties and rock star shenanigans in my head. And he'd have mine (not that those would impress him, I’m guessing). Plus, I would be able to play guitar like he does, and he could do my job (again, not that he’d be likely to). Pretty trippy, huh?Think about it for a second. What would happen?Let’s start with this: what if you had gotten away with a murder, which had no witnesses, and which had gone unsolved? Suddenly you've got an Other out there, who knows all your secrets. What would you do? What would your Other do? And speaking of secrets, what about national security? What would the governments of the world do if suddenly their most closely guarded nuclear designs, tactical plans, and undocumented alliances were suddenly shared by a random smattering of Others around the planet? What would happen in places like North Korea or Belarus if suddenly the whole population got foreign memories of how good things can be on the outside? What would you do if you woke up with an insider’s knowledge that company X was planning a hostile takeover of company Y? If you made stock trades based on this, would it be insider trading? What if you knew country A was secretly planning to invade country B? What if you woke up with an insider’s knowledge about who really killed JFK? Not all of these are addressed in the book, but Cinco de Mayo does a nice job of examining how much of our grand social structure is balanced precariously on keeping secrets. Perhaps I’m dwelling a bit too much on the secrets angle here though, because the book goes far beyond that. Cinco de Mayo also ponders (is ponder the right word? this book reads pretty fast) the significance of shared experiences: What if a practical-minded skeptic got the memories of somebody who’s had an out-of-body experience, or somebody who has floated up that tunnel towards the light as their body lay dying on an operating table? How would a shaman of an indigenous tribespeople process the memories of a clinical researcher at the National Institutes of Health? What would a man who’s been blind all his life in rural China do with the sighted memories of a Wall Street high roller? How might a French playboy have an amazing opportunity to give one family a lot of joy, when his mind is paired with a severely mentally retarded boy in Appalachia? What would an abused housewife do with the martial arts skills of a Swiss special forces agent? Well... you might be able to guess that last one. My point is that there are a TON of cool and completely plausible stories which might grow from a single “what if”. Cinco de Mayo follows seven or eight paired Others, exploring just a few of the more imaginative possibilities. The other entertaining aspect of the book was how it handled the actual memory swapping phenomenon. This novel would be complete and entirely satisfying if it never went into all that; Mike Martineck could have left it unexamined, like the apocalypse in Cormac McCarthy’s The Road, but instead he goes an extra mile for the reader. Naturally, the empirical evidence afforded by planetwide memory swapping is neither predicted nor explained by established theories of how the brain works. Attempts to scientifically study the phenomenon would require significant broadening of most researchers’ minds. Cinco de Mayo follows a group of neuroscience experts as they develop theories about how and why the mass-swap happened. Okay, I get that this is fiction, and attempts to delve too deeply into fictional science tend to result in über-nerdy discussions about the optimum number of flux capacitors in a warp engine, or some such nonsense, but this book actually comes up with some very clever theories, which are fun to read. Psych majors may be enjoy hearing read why Carl Jung’s stock may rise, should one of these global paired-memory swaps ever go down IRL. Overall, Cinco de Mayo was a fun, intelligent, and fast read, which left me wanting more. (TWSS)Note: If there’s any cosmic force out there considering visiting a mass memory swap on the people of Earth, could I make a request? I’d like to swap memories with Manny, because I don’t envision myself ever getting that good in chess by conventional means. a porn star.