At some point in near future aliens visit Earth bearing ill tidings – both the planet itself and humanity is screwed, and only hope for survival is to take their offer of one-way trip to twin worlds of Castor and Pollux where new life awaits if they take up the dogma of Harmonious Unity where things and beings don't compete, but cooperate in existence. Earth's problem is ecological in nature and fingers get pointed at humans for essentially ruining the world as carefully selected pools of people embark on this arduous journey to unknown worlds aboard arks grafted to living Beastships with mysterious Arthroplana acting as pilots. Amusing bit is all of the above is just the opening of the novel which then jumps two thousand years forward after humanity has settled on twin worlds with generations upon generations accustomed to the new way of life under the watchful eye of Human Conservancy as their lives become longer. Until the main cast gets involved with Earth Affirmed's generation spanning question and agenda regularly ignored or snuffed out by the Conservancy – what happened to Earth?

There's multiple POV characters, even couple of surprise ones novel springs on you, but initial ones include; John, Connie and Tug – human captain, crew and Arthroplana pilot of Beastship Evangeline, respectively. Much of the appeal of Alien Earth lies in observing this now-alien society through the lens of people who happen to be outsiders as taking the job of Mariner manning Beastships is precisely that. Arthroplana, with their long spanning lives and access to living ships in a setting that abhors “dirty tech”, have a monopoly on space travel and seeing as trips are done in real time human crew undergoes extensive periods of Waitsleep similar to suspended animation. This means John and Connie are akin to Methuselahs to the rest of human population as they don't belong and see the cycles repeat, on and off. Being one of the enigmatic alien race Tug is an interesting counterbalance to two humans as he cannot leave the Beastship he pilots and it's implied humans are on-board said ships as sort of intellectual amusement for decidedly alien pilots.

I've already done too much summarizing and not enough opinions so I'll stop with the former, but THEMES are on full display in Alien Earth.

You'd think this is ecological SF, but I'd argue against it. Biological “technology” has largely replaced conventional tech as it is degradable and adheres to the most important tenant of Unity – humans must leave no trace. This should already be triggering some red alerts, but on Castor and Pollux everything is in such perfect cooperative harmony that humans end up living as mere observers. One character even brings up an anecdote of what she did earlier in life where her job amounted to carefully weighing how many petals fell of trees and adding precisely the same amount of nutrients to keep everything balanced. Day in, day out. This ideology is then pushed to the extreme with some minute events like a child stepping on grass leading to, back in the day, exile to life on stations or, more recently, euthanasia. Not the mention the infamous Readjustment process if you're not perfectly in line with Harmonious Unity. Humanity has seemingly accepted this as way of life or even punishment for their perceived “human guilt” of destroying Earth as that is the accepted message. All of this is further muddled by the fact Conservancy continually excises, edits and obfuscates old information as select people delve into illegality to preserve bits of history, but most are content to live out in comfort as their history fades making them lesser in the process.

Alien Earth does that thing I like with an unfamiliar setting in that it consistently drip feeds you bits of information on every page. As captain John verbally spars with deceptive Tug you also get tidbits on why so few people live on twin worlds, for example. I have to admit this was huge part of the draw until about halfway into the novel when plot proper starts and oh boy, does it kick into overdrive in the last third or so. Character breaking-the-sound-barrier fits more than “development” in this case, but there was some awkwardness to how sudden and aggressive it is... until I realized it's a perfect response to in-universe situation. After all, how would absolute freedom change you? Certain line about “taking our language and giving us a slave one” was a bit to on the nose, though.