Publisher: Avon Books (Mm) (Jun 1996)
In the same universe as Arrow From Earth, this one works less well. The idea of the Habegger Gates is less well exploited, but the main problem is the existence of multiple (and confusing) races of aliens, who have an early form of space flight. Trying to keep straight which race was in view, and therefore which faction was active, was a pain, and that I finished it is possibly because I fail to finish very few books indeed. It's not as bad as some books out there, but I'd say that it's probably the worst I've encountered by Busby.
(In case you're wondering, no, I've not explicitly a fan of his - I just encountered a stack of books second hand, and had reasonably favourable memories of his work. So I bought the lot, and went through them in short order.)
OK, but not recommended.