A return to the genre of the supernatural for Straub, Mr. X nevertheless closely follows the same clues-in-plain-sight structure as his mystery novels Koko, Mystery, The Throat, and The Hellfire Club. Ned Dunstan has returned to his home town to see his dying mother one last time, and as he does so the secrets surrounding his lineage slowly begin to unravel. Ned has always been plagued by visions of a mysterious killer he calls Mr. X, and as he comes closer to the truth about his connection to this shadowy madman, he discovers he comes from stock that's something more than human. His relatives all share certain frightening abilities, though it's not something that's ever been discussed or displayed in front of him, until now. (Interestingly, this is the second novel in a row I've read about a family that shares extraordinary abilities, the other being Rhodi Hawk's marvelous A Twisted Ladder.) Soon Ned discovers he has a twin brother he never knew about, Robert; a brother who, to paraphrase a line from Lovecraft's "The Dunwich Horror," which so deeply influences and informs Mr. X, is more like their father than Ned is.
Mr. X himself is a fascinating character, a killer who, after reading a Lovecraft collection, believes he is the direct descendent of the mad, cosmic Old Ones. While there's no doubt he, too, is something beyond human, there's some wiggle room as to whether he's truly delusional about his lineage. After all, the novel takes place in a world where, as we discover, the old gods are quite real. For instance, the great god Pan, we're told, has become a homeless, destitute jazz musician named Goat Gridwell. So who's the say that in this world Yog-Sothoth isn't actually spawning half-human children? (While much is made of "The Dunwich Horror," only one other Lovecraft story is directly referenced by the plot: "The Shunned House." As an aside, I know tastes differ, but I've always thought of "The Shunned House" as one of Lovecraft's more boring and by-the-numbers stories. Though I do love that elbow.)
Mr. X is an immensely satisfying read, doubly so if you're familiar with Lovecraft's oeuvre, but there were a few things deliberately left ambiguous that I would have loved to see answered. What exactly is the Knacker, for instance? While it seems to be inspired by the black, tarlike residue left in the Dunwich Horror's invisible tracks in the Lovecraft story, there are tantalizing clues that it may have played a role, much like the meteor in Lovecraft's "The Colour Out of Space," in the "tainting" of the Dunstan line. I also wanted to know which god was represented by the big man in the daishiki that Ned keeps meeting, and what the significance was of the initials and date carved into the table in Ned's hotel room. Of course, when you're dealing with the supernatural, especially of the cosmic variety, a little ambiguity is a good thing.
Once again, as a writer I find myself both inspired by and humbled by Straub's abilities. Like all his novels, Mr. X makes me want to be a better writer; and like all his novels, Mr. X makes me so very, very glad to be a reader.