I've now finished. Here's my thoughts on it:
Wow, what a bleak, horrific universe that Barron presents in this collection. An array of veiled glimpses into the crawling chaos are collected here with these superbly well written stories.
There seems to be a strong if somewhat nebulous theme running through his work not too dissimilar from Lovecraft's in that there is a harsh, terrifying universe out there lying just beyond the bounds of our everyday perception but that occasionally people stray beyond that veil of ignorance and find out more than is good for them (and their sanity). This is demonstrated most clearly in stories such as "Mysterium Tremendum" and "The Broadsword". Some distant and lingering descendents of an ancient alien race wants us, to transform us into something quite terrifying, but not so much physically as psychologically. Sometimes this manifests itself in more traditional ways such as satanism and the occult in the stories "Catch Hell" and "Six Six Six". And other times it is only to reveal the depths to which humanity might sink with the unscrupulous underground artist in "Strappado" and a man who gets caught up between some strange cult and the insane vengeance of his ex lover in "--30--".
Stylistically, Barron never tells you too much, painting a picture of scarce, loosely connected details that the reader must read in between, fill in the gaps to complete the terrifying vision as far as they dare. It is all delivered in a rich, evocative prose in which the careful choice of words is just as important as the plot itself.
I found this collection to be of a consistently high standard throughout with no weak entries. If you are a fan of intelligently written horror and have not read Barron before, you will definitely want to read this. If you have read his previous collection "The Imago Sequence and other stories" then you will likely agree with me that Barron has gone on to even greater heights with this collection.