Somebody made a comment here that made me think it might be worth clearing up a point of potential confusion arising from the fact that even though Stealing Light is the first of a projected series of three, you couldn't necessarily tell that from picking a copy up in a shop. It's not like it actually says 'Book One of the Shoal Sequence' anywhere on the cover or inside. Here's why.
It's because of the way certain contracts panned out. There was a contract between me and my publishers that included Stealing Light, but not necessarily anything beyond that. As a result, Stealing Light sold as a standalone novel. It was only during the course of writing it that it occurred to me I might be able to either extend the story in interesting directions, or write other stories set within the same universe.
I think it's fair to say the publishers really liked Stealing Light. Liked it so much, in fact, that they followed up on a passing suggestion on my part via email that I might be up to extending it into a series. At this point the book hadn't yet been published. Further, I suspect they wanted to watch and wait to see how well this book did before necessarily asking for more of the same.
As it is, the contract for another two books got signed pretty quickly, and I'm working on the second right now. If you want a point of comparison in terms of how things worked out, an example might be the way the movie Star Wars ended up getting made.
Star Wars is a movie with a very distinct ending. When it's over you think, yeah, it's over. We all know Lucas already had plans for other movies, but nobody was signing on the dotted line until they saw how that first film performed in the cinemas. As a result, Star Wars - despite being subtitled 'Episode Four' - was required to be an entirely self-contained narrative. That there was room for sequels (and, unfortunately, prequels) was obvious and ultimately fortuitous. You could say the same for the Back to the Future movies.
Which is kind of why Stealing Light ended up with sequels but doesn't say 'Book One' on the cover. It could, but I'm not sure whether or not it should. I like to think anyone could pick it up, read it, and feel like they'd read a finished story without necessarily being mugged into buying another book to find out what happens next - but that's not to say there aren't strong hints in the narrative to suggest what might be coming if they chose to read more.
I wasn't sure until fairly recently whether Book Two was going to be a direct sequel or a separate narrative set in the same universe. As it is, it's a direct sequel. I can't even say for sure if Book Three will follow straight on from Book Two, although it's starting to look very likely.
I'm about halfway through book two at the moment. I suspect it's going to end in such a way that again you feel like you've read a complete story, with a definite end ... but with big fat teasers to suggest something really, really cool might be happening in book three, should you choose to buy that when the time comes. In fact, let's not call it a trilogy ... let's be really up the ass and call it 'three sequentially linked but nevertheless distinct narratives'.
I'm not ruling out the possibility of a separate novella set in the Shoal universe at some point. There's a story I have in mind that's currently intended to be part of Book Three, but I'm not sure yet whether it'll fit in neatly with everything else I'm expecting to happen. If it doesn't quite fit, I may write it as a separate story.
Hope that clears up some potential confusion.