Some book writers are novelists and some are story tellers.
Lilith Saintcrow (a name which, somehow, I can't find it in myself to take very seriously) is a born story teller who suffers under the delusion that she (he?) might also be a novelist. This is made amply clear by the regular haltings of the story for flashbacks to protagonist Jill Kismet's (another ulikely name) unhappy past, to her self-loathing, to her drippy religiosity and to her just plain generalized kvetching. None of these little italicized episodes is very interesting or even especially successful in any other way, so you might as well skip over them.
What merit the book possesses is to be found in the story telling. Author Saintcrow takes us on a fast, bumpy ride through a variant on the Buffyverse--and not a very variant one at that. Jill Kismet is a slightly older, much coarser Buffy. Jill had a much less pleasant childhood and she seems utterly to lack Buffy's talent for accumulating friends.
As fictional worlds in hiding just around the corner from our own familiar surroundings go, Kismet's universe really doesn't make a whole lot of sense. And I give Saintcrow heavy credit for this, she doesn't seem to give a hoot about any of its logical failings. Jill Kismet's world is full of powerful entities such as "hellbreeds" (i.e. demons) and "weres" (i.e. shape changers) who look and act just like urban lowlifes--as they might be imagined by yuppie suburbanites, that is.
Saintcrow's insouciance with regard to the "weres" actually becomes rather amusing as the book rolls on. First, she appears to be unaware that the word "were" as in "werewolf" is the Old English "wer," a cognate of the Celtic "fir" and the Latin "virum," all of which mean simply "man," so that a "werewolf" is literally a "man-wolf." She applies to her "weres" the social relationships of some but by no means all predatory pack animals, but she also has them living on "reservations." Her "weres" are terse of speech, darkly handsome, physically competent, stolidly noble and otherwise generally described in such ways as to make me believe that the author has never so much as met an inhabitant of any real reservation, such as the one six blocks from my house.
And, of course, her "weres" are not mere wolves in human shapes--oh, heavens no, they come in tribes: cats, canines, birds, snakes and spiders. This last, in particular, is a delightfully lunatic notion that provides one of the highlights of the book.
The strength of "Night Shift" lies in its ability to make the reader wonder what is coming on the next page. You can't get ahead of this author because her story does not have any significant line of logical progression. It starts, it veers and swerves all over the place, then it ends. And, what the heck, if the final payoff is not really commensurate with the build-up, well, who cares? It's the ride that's fun, not the destination.
By any objective standards, this is a three-star book--not bad, not especially good. On the other hand, if you are willing to ignore your logical filters and just go with the rush, you might find four stars more appropriate.