Almost 3.5 Stars 
 Interesting concept. Dark, grungy, and a touch whimsical (particularly when it comes to the alternate-reality pecking order of certain rodents.) 
 In a Nutshell: Richard Mayhew, a weak-willed and unremarkable man, loses it all when he decides to help an injured girl. His version of reality rejects him, and he finds himself in a parallel London fraught with urban fantasy danger. 
 "There are two Londons. There's London Above--that's where you lived--and then there's London Below--the Underside--inhabited by the people who fell through the cracks in the world. Now you're one of them." 
 But Richard has an agonizing amount of difficultly accepting what's happened to him. Even when he does, his dull inability to adapt to new cultural and conceptual nuances makes his survival seem more than improbable. 
 While this reader never formed any particular empathy connection or attachment to any of the characters, the biggest problem for me was Richard Mayhew. He was so dense and lacking in sensical self-respect, I just couldn't cheer for him. I would call him TSTL (Too Stupid To Live), but the author is British and so is the book's setting. So I guess that makes him TDTL (Too Daft To Live.) Fortunately, the point of view isn't limited to Richard, and actually does a lot of moving around. (I'm not sure I could have made it through if I'd been stuck with him alone.) 
 At one point, well past the middle of the book, Richard takes on this attitude: (view spoiler)[ Oh, so the people who've been keeping me alive in this horribly dangerous place think I shouldn't be consorting with this mysteriously interested woman. But surely I know better than they do about the potential hazards of their world... >.> (hide spoiler)] 
 Oddly enough, the threads of this book left unanswered held better in my memory than the plot itself did. (view spoiler)[ 
 -What was Hunter's curse? What would have happened if she'd gone to London Above? 
 -Is Door really the last of her family left alive? 
 -Why was Richard able to see Door in the first place? 
 -Why would Richard even consider choosing the unmitigated horrors of London Below over the reality he is accustomed to? 
 (hide spoiler)] 
 The intention may have been to leave room for a sequel, but to me, it just ended up feeling like the worldbuilding was less distinct than I would like--fuzzy around the edges. 
 I generally like Gaiman's works better when he writes shorter. Although in this case, I liked it only slightly more than American Gods but not nearly as much as Stardust or The Graveyard Book. (Where that sits on my sliding mental scale, I'm not even sure.) I also think there's a bit of a pacing and info buildup toward the end, which made the last 15% of this book significantly more interesting and satisfying than much of the rest of it had been--at least to my mind. 
 Favorite Quote: 
 "I have always felt that violence was the last refuge of the incompetent, and empty threats the last sanctuary of the terminally inept."