The Archie Sheridan/Gretchen Lowell series is into its sixth book in seven years with the just-published LET ME GO. That’s not bad at all for what I thought would be just a trilogy. Chelsea Cain, the author of this (hopefully) never-ending wild night’s ride, seems to have an inexhaustible mine of ideas that keeps each installment as new, fresh and, yes, gory as the first.

Hold on. I mentioned “gory,” but I haven’t said anything about “erotic.” Let me correct that omission right now. If you are unfamiliar with the Sheridan/Lowell books, please be advised that, taken collectively, they are one long love story. Sheridan is a task force cop, and Lowell is a serial murderer whose capacity for inventiveness exceeds that of Nikola Tesla. The overriding theme is that Sheridan chases Lowell until she catches him. This is true, even in the books where Lowell is arrested and incarcerated, though only, of course, as long as she wants to be. In her own very deranged way, she is in love with Sheridan. As for Sheridan, let’s just say that Lowell has gotten under his skin in more ways than one.

"Lowell wants to give Sheridan a birthday present he will never forget, and she does, in three different ways you may never forget."

Similarly, the title LET ME GO has multiple meanings that echo and resonate throughout this tale from start to finish. It begins with Sheridan’s birthday, which ironically enough is just before Halloween. Sheridan is investigating the murder of a DEA agent, but gets presents galore, even as Lowell, who has recently escaped from prison, casts a shadow over the celebrations and the holiday. Just to keep things as bizarre as you might expect them to be, Sheridan semi-crashes a masquerade ball held on an island owned by a notorious local drug kingpin. Unbeknownst to Sheridan, at least at first, is that Susan Ward, a local freelance journalist and Sheridan’s erstwhile soulmate, is also at the party. Interestingly enough, it appears that Lowell has been there as well, apparently manifesting her presence by leaving the body of a murdered woman behind. The killing, however, lacks Lowell’s trademark theatrical elements, so that while he has plenty of sins for which to atone, the party murder may not be one of them. Another killer appears to be on the loose.

Lowell wants to give Sheridan a birthday present he will never forget, and she does, in three different ways you may never forget. There are also flashbacks that shed some insight into the relationship Sheridan and Lowell had before he discovered she was a beauty killer. These more than likely will slow your reading down a bit, given that it’s difficult to peruse the printed page when one’s eyeballs are steamed up from the inside. That the flashback is dropped right into the middle of an extended climax makes the contrast all the more startling and memorable.

Chelsea Cain simply becomes more impressive with each new offering. The narrative seems to spring from an unbridled imagination, but for some reason, I have the feeling that her storytelling, as wild as it may be, is exercised with restraint. It doesn’t read that way, but my instinct tells me that she is just warming things up for us and that the very best is yet to come in waters heretofore uncharted. Readers might need a note from their doctors before they’re permitted to purchase the next installment. It will be worth it.