Into Richard's world steps, or rather stumbles, Door, an oddly gifted teenager fleeing assassins. When Richard stops before her crumpled, bleeding form in an act of true human compassion (thereby ungluing his precariously cemented engagement to the affluent and vapid Jessica), he begins his descent into the maze of lost time and lost places that is London Below. This single moment of human connection drops Richard through the cracks of the structured and scheduled into a terrifying abyss where archetypal incarnations of human nature roam: Beast and Hunter, Torturer and Victim, Savior and Destroyer.

It's here that Richard's inadvertent journey of self discovery begins. Yes, this is a quest novel, but the object is not simply to find a key. It is, more importantly, to discover the true nature of self. Richard -- unassuming, claustrophobic, and afraid of heights-- must plumb his own dark crevices while navigating a labyrinthine microcosm that both crushes and expands the very notions of time and place. And all he really wants to do is get home.

One of the most intriguing aspects of this novel is the development of London itself as a character. The lucid London Above is linked with yet totally oblivious to the roiling chaos of London Below. Only the truly dispossessed (rats, the homeless, the insane, the runaways) can negotiate the boundary between the two. For the Londoner above one false step, one break with the chain of rationally structured events, and the veil lifts, the invisible emerges and the dark chasm of Below yawns. Richard's goal is to clamber back out of the pit of irrationality, dream and danger -- if he can. As Richard explores himself, so too does he unearth every corner of the twin cities. (Mind you, I'm not actually saying ego/id, conscious/unconscious, but you get the picture.)

In case the plot doesn't send you, the writing has moments of sheer brilliance. The bad guys, for example, are really bad, with a laugh that "sounded like a piece of blackboard being dragged over the nails of a wall of severed fingers." Gads, that makes one's skin crawl. Gaiman beautifully orchestrates scenes, fractionally unveiling psychological and physical terrors until the unwary reader totters as unsteadily as Richard on the brink of this terrifying world.

You may have gathered that I really liked this novel. I'll admit I don't know how to classify it: sci-fi, fantasy or psychological thriller. In fact I don't know how to label this at all except to call it very, very good.