Basically as of right now it’s in limbo.
I’ve been talking about it like it was a certain thing, but in this business very little is actually certain, and currently the book has no publisher. Self-publishing is really not all that feasible right now for a number of reasons, nor is it at all ideal. I’m exploring some other possibilities, but selling a sequel absent the first book seems to be very difficult, so… While I hope it happens, it may very well not.
It makes me sad to think that Line and Orbit was the last we’ll see of Adam and Lochlan. Hopefully it won’t be.
When there’s news, you’ll hear it here first. And in the meantime, there’s Labyrinthian, so be looking for that.
A Trick of Light 
Argh that’s such a shame but I can understand why you wouldn’t necessarily want to self-publish. Although I do hope a sequel gets published at some point. And I’m definitely looking forward to Labyrinthian.