This is, unquestionably, a Tim Powers novel. That means that it features a moderately large cast, ranged along a continuum from the mostly heroic to the wholly villainous, a slightly under-motivated romance, a lead character who makes some serious early mistakes that nearly get him killed and leave him in a difficult predicament, and some stunning reinterpretations of the world as we know it in terms of the supernatural.
This time around, the conceit is that the bums who wander the streets of Los Angeles are in fact ghosts who have taken on substance, and that the real drug scene in L.A. involves inhaling ghosts for a rush of their memories. Here as in his other novels, Powers takes his conceits seriously, spinning out a wealth of subplots and details in a demented and yet utterly believable fashion. Addicts attract ghosts with palindromes and bottle them for later use? Sure. Thomas Edison invented a device for talking to ghosts? Of course. My only caveat is that the ending is a bit more of a rolling stop than a bang.