The story starts with Marine sniper, Miles Reardon, being assigned to duty at a top-secret facility to provide security for a rather bizarre investigation. This is deep underground and the deeper you go, the more dangerous the problem. This level is below Ebola, Marburg, etc. Every science fiction story is entitled to one bizarre proposition, and in this case we have Barry who is coated with something they call "The Taint". This conveys supernatural properties and feeds on colour. It simply takes the colour out of anything, leaving behind grey, and while doing so, covers more and more of Barry. The more he is covered, the stronger the effects. (Exactly how Barry got to this facility is unexplained – a day of bright sunlight outside and he would be completely covered.) A rather bizarre and dysfunctional group of weird specialists is brought to try to understand this phenomenon.
The specialists are primarily egotists, and in some ways the story highlights some of what is wrong with modern society, and especially modern science. They are all so specialised they have no interest in anything outside their own specialty and Barry, or the Taint, feeds on this, giving them increasingly more powerful additions to their specialty as long as they feed it colour. Each specialist has only one objective: to get what they can for themselves. As you might imagine, this leads to . . . Well, it leads to the well-written and well-developed story. A warning: the author did his best to annoy me with some of the more bizarre aspects of quantum theory that were presented in a way that really, have salt nearby. Nevertheless, a well-done story.