Boundary is a fun book. The characters are engaging, interesting, and more than just one-dimensional. It's refreshing to have a book with soldiers, scientists, and secret agents, all of whom, even when having differing orders, still find ways to actually work together for the common good. It's a story of people working together to solve a mystery. Not all the people have to like each other, and not all the people have to like the way things are done, but still, having spent many years in academia, and a few working for NASA, the settings and situations were not at all unfamiliar. The only real stretch to the imagination is that NASA is capable of actually performing anything like that depicted in as short a period of time as is postulated and actually have it work.

There's a good deal of technical wiz-gimmickry thrown around, and the authors have to take time out here and there to have one character explain it to another so the audience doesn't feel left out, but in general it's done smoothly enough that you don't feel like you're being given a lecture. And the wiz-gimmickry stuff is pretty neat anyway.

The only potential problem is that the ending doesn't wrap up many of the questions presented in the book. Since it would be inconceivable to me to have the characters come up with pat answers to alien mysteries from across time and space, this wasn't that big of an annoyance to me. But I know others like to have the puzzles all neatly tied up, so let the reader beware.

Recommended.