A straightforward "inquisitorial procedural". Ravenor and his team investigate the mysterious drug trade in "flects", highly-addictive warp-tainted shards of glass being pumped into Petrograd by persons unknown. The team rattle some cages, piss off the wrong people, and have a few scraps. I won't spoil the ending but it doesn't take a great leap to imagine how it goes.
This is textbook Abnett, Black Library's talisman and most talented writer by a significant margin. I must say I did not enjoy it nearly as much as I did Eisenhorn (or Abnett's other BL offerings, such as Gaunt's Ghosts or some of the Horus Heresy books). As Senior Canon Generator, I admire Abnett's ability to flesh out the 40k universe in a way which makes it feel like a functioning, if nightmarish, religious bureaucracy, and he brings a level of maturity to a universe that can otherwise be very silly. This book, however, while all the ingredients were there, did not enthrall me as some of his other novels have done, and the large number of references to the female characters' ample assets wore a bit thin--much like their outfits--after the 5th or 6th time.
A "I liked it" 3 stars, but in reality a "just-north-of-2.5-it-was-slightly-better-than-just-ok" stars.