Wow. No kidding, this is the best “big idea” SF I’ve read in a really really long time. It won some awards (back in 2015 when it was published), but not enough of them by my lights.

The basic setup here is that, in the nonspecific future, humanity realizes that the damage done to the Earth is cascading and irreversible, and so as a way of saving the species ambitious terraforming projects are undertaken at apparently-viable extrasolar planets. Obviously there are all very far away, and there’s no magic FTL drive on offer, so cryosleep is the answer.

This means a long gap between “let’s go out there and terraform” and “let’s go move there,” and of course politics gets in the way. The mission is started, but before anyone can actually establish a colony on one of these worlds, infighting and nation-scale wars more or less knock humanity back down the tech ladder quite a ways.

While life on earth drifts backward, though, the terraforming folks are doing their work. On one planet — Kern’s world — the idea was to seed it with monkeys infected with a beneficial nanovirus (the plot-driving handwavium here) that allows for generational learning and accelerated development. Cool idea!

But! As that monkey-seeding was being undertaken, the station is struck by a weapon from a rival Earth faction, killing all the monkeys — and releasing the nanovirus to infect another formerly earthbound species: Portia labiata.

Thousands of years later, we pick up the tale with two parallel threads.

The first is with successive generations of now-intelligent spiders as they evolve from effectively a tribal existence to the basics of a spacefaring (or at least satellite-capable) civilization. What does intelligence and technology look like for an uplifted spider?

The second POV is aboard a ship of pilgrims from the new, second round of Earth-based intelligent humans. They have independently developed space travel; previous Earth tech is mostly impenetrable to them (and far beyond their ability; they refer to all that as Old Empire stuff). As before, they’re seeking a new home, and have become aware of the terraforming project at work on Kern’s world.

The problem with “big idea” books is that sometimes that’s all there is. I find books like that dissatisfying. I was NOT dissatisfied here. Tchaikovsky does a great job of exploring the universe he’s created, and coming up with really fascinating turns that nevertheless still fold into the story in organic, elegant ways. Both spider and human confront and move through a variety of challenges as the book marches towards the obviously inevitable conclusion (ie, who gets to live on Kern’s world?).

One very cool aspect here is the way he uses points of view. For the humans, it’s kind of conventional: We have some set of “Key Crew” of the pilgrim ship who slip in and out of cryosleep over time, which allows one — a classicist (meaning he studies “Old Empire” stuff) named Holsten — to be our main eyes and ears for their tale. This consistent POV is a great means of continuity, and also allows the Tchaikovsky to emphasize how alien a “baseline” human has become vs. the generations eventually born on board the ship.

But, as I said, that’s the “normal” part. On Kern’s world, our point of view is nearly always from a spider named Portia, but each time we switch back to the spider narrative it’s a later spider with the same name. Again, the timeline of this book is at least 2,500 years, and we follow the spider civilization through a number of crucible moments and existential threats. The series of Portias have associates with recurring names as well. This may sound weird but it works REALLY well. I was super pleased with the conceit; it gave the story continuity without complicating things with a long list of names you’d read once and lose.

Tchaikovsky has written a really wonderful example of what Big Idea SF can do and be. It’s probably not going to surprise you that you find yourself on the spiders’ side in the inevitable conflict, which is a neat trick when the other side are the last remaining humans. What may surprise you is the degree you find yourself reflecting back on the themes built into the story, and interwoven between the two narratives; by the time you get to the end, you’ll realize the somewhat surprising conclusion was where the book was going all along. It’s a lovely moment.

Anyway, this book isn’t small — it’s 500+ pages long, but reads quickly.

Here’s the Wiki page. There are two sequels, and I’m sure I’ll get to them before the year is out.