Apparently the book has a different subtitle depending upon where it was published. In the US it's "A Scientific Romance." In the UK it's "A Novel of First Contact." I suppose it depends upon how you define romance as to which is more apropos.
The story involves a human generation ship arriving in a new solar system only to discover that an industrial age civilization already inhabits the second planet. It's the first time in 14,000 years of interstellar colonization that humanity has run across any life more complex than single cells, so it's a bit of a shock. Meanwhile, down on the planet, an astronomer searching for a new planet discovers the ship.
As previously noted, I had some trouble getting into the book. It alternates chapters between human and alien point of view, and I was enjoying the alien side far more. I finally figured out that I had to flip my frame of reference. The "humans" on the ship are actually more alien (to me) than the "alien space bats" down on the planet. The aliens even refer to themselves as "humans" (presumably translated from their own language.)
The human chapters are split among three viewpoints, one from each ship faction: founder, crew, and shipborn. (Humans are for all practical purposes immortal.) The founder and crew viewpoints are third person, while the shipborn viewpoint is told through the blog entries of a 15 year-old girl. Her name is Atomic Discourse Gale, and she is extremely precocious and knows everything about everything. The founders don't want to interfere with development of the aliens, and want to slow things down. The shipborn just want to get on with the business of colonizin' and making money hand over fist. The crew just want to move on to the next star. There's an interesting contrast between the founders and the shipborn. The founders have been on the ship far longer than most of the shipborn, but that time is for most of them just a small fraction of their lives. What's another couple of decades to sort out how to deal with the aliens to them. The shipborn have been on the ship for <whine>their entire lives</whine>, which of course seems like forever to them, even if it's only been fifteen years or so. The thing is, I don't really much care about any of the human characters, especially young Ms. Gale.
The aliens chapters are told strictly from the third person viewpoint of the astronomer, and to me were far more interesting. This is where the romance of science comes in. While the human factions are mucking about arguing over interference and high finances and OMGWTFALIENSPACEBATS, the aliens are doing science. Chad Orzel recently wrote a post about things that people should understand about science, and the first thing he mentioned was that "Science is a process, not a collection of facts." The astronomer's friend in the book echoes this, opining that students learn the known, while scientists learn the unknown, and the book does a creditable job of showing the process.
The ending is more of a whimper than a bang. It's also kind of an abrupt whimper. With about fifteen pages to go I was still wondering how MacLeod planned to wrap things up, because it seemed like he wasn't even close to a resolution of the story. Unfortunately, he didn't really wrap things up. Instead, exposition girl gives a brief run down of events in a blog post ten years later on how everything worked out far better than most expected. It's not very satisfying.