If one were to isolate the first 250 of 400-odd pages of The Overnight and present them to a reader, without identifying the author or genre, this reader might easily ignore a number of small incidents or explain them as the doings of a disgruntled employee, or chance. I realize that this builds the atmosphere, but I must admit to skipping paragraphs. The remaining 150 pages are much like the films Alien and more recently The Cave where the humans in an enclosed area are picked off one by one. To Campbell's credit he doesn't let anyone get away -- no Ridley to blow away the nasty beasty -- and portrays the claustrophobic atmosphere of the fogged-in store, beautifully.

I am a great fan of atmospheric/psychological (over blood and gore) horror as my comments in some other reviews (1, 2) will attest, but, in my opinion, with the possible exception of Dorothy Macardle's Uneasy Freehold (1941; a.k.a. The Uninvited), and perhaps one or two others, novel-length atmospheric horror just doesn't work very well. If one looks at the works that have made the reputation of atmospheric horror writers -- British (E.F. Benson, Algernon Blackwood, M.R. James, Oliver Onions, and more recently Robert Aickman) and American (Edgar A. Poe, H.P. Lovecraft, and more recently Thomas Ligotti) -- it is their short stories or novellas at best. Who remembers Algernon Blackwood's novel The Fruit Stoners over his "The Wendigo?" Event-based, blood and gore-driven or supernatural horror has from the Gothic era been able to sustain the novel length, but expand the succinctness of an atmosphere-driven horrific situation/concept beyond its capacity and it simply becomes tedious -- even if it beautifully written.

Campbell's The Overnight is a work where the mechanics are well, even beautifully done, but placed in a form not best suited to it, something like placing a Ferrari F-1 engine in a school bus.