If you did read "The Patterns of Chaos" by the same author, and you did enjoy it, you simply have to read this book (as with "The Patterns of Chaos", I read "The Chaos Weapon" for the first time when I was very young). This is not the continuation of the other book, but the concept of "Chaos" is almost exactly the same. The main story involves Space Marshal Jym Wildheit - teamed with a half-grown (but lethal) woman Sensitive, and an "invisible god" perched high on his shoulder - on a mission aimed at the strange device that was distorting probability and threatening the entire human Federation (Wildheit is assigned to find out what is causing those distortions and to eliminate the threat to humanity). This is also the book in which you will meet Kasdeya, Penemue, Gadreel and Asbeel - and few other characters who greatly influenced some of our "myths" from the past.
It is a short read with some excellent SF concepts and is a nice "addition" to the "Patterns of Chaos" (you could actually say that both books - in a small way - complement each other). Even though the character development is not very deep here (but it is also far from "basic") and the story itself it not very complex (in fact it is quite simple) - it is still a very enjoyable book to read for any fan of SF from the 1970s. Long time ago I would give it a 5 stars review (but then again, I was much younger back then), but today I would say it's a solid 3.5 (approaching 4) from me.