A few years ago, when I'd bought that Thin Man movie collection for my dad, it was pointed out in the comments section that Hammett was a fan of what the movie did with his book. And it turns out my dad owns the book, so I wanted to read it and see.
Keeping in mind it's been two years since I watched the film, the book started off feeling very similar. The partying into the wee hours of the morning, Nick's incessant drinking, Nora's fascination with all this murder and intrigue. The language is a little coarser (there's a couple of "bastard"s in there), and Asta isn't nearly as big a deal, but the feel is similar. Nick has no particular interest in investigating anything, but people keep bugging him, and that in turn, makes everyone else think he is investigating. Soon they're all confiding in him, or bouncing theories off him, and he pretty much can't help but solve the case.
The further into the book I got, the more I thought I started to see differences. The Wynants - Mimi, Dorothy, Gilbert - were a thoroughly miserable bunch. Always lying about each other, or to one another. All trying to ingratiate themselves to Nick and Nora, always flying into hysterics to play on someone's sympathy. But looking back at that earlier post, I mentioned being disappointed the killer was not one of the unpleasant characters I'd grown to despise, so maybe not so different.
Even so, the book did have a grimmer feel to it than the movie. Maybe that's the absence of Myrna Loy and William Powell. Even though I was picturing them as I read the book, it still isn't the same. The dialogue's different to be sure, but the inflection they'd give it, their expressions, the music that goes with it, all that could give the film a lighter, more cheerful feel of a couple of rich lushes staggering their way through a homicide investigation they don't really want to be involved in. Also, I think Hammett focuses less on the interaction between Nick and Nora, and more on Nick dealing with the Wynants. Nora feels like more of a tagalong, the audience representative who gets Nick to explain his thinking for us. The difference between a story about a couple who investigate a mystery, and a story about a mystery investigated by a couple, as I said back then.
Taking the book on its own terms, it's pretty good. I missed the true killer, as usual, but looking back, it seems plainly obvious. I got fooled at one point into believing the fat man in the bar, who was soundly beaten by old criminal acquaintances of Nick's was involved. In retrospect, that seems to have been nothing other than Studsy and the rest objecting to the guy giving Nick grief. That and their being in the mood for a little violence. Hammett paces things in such a way that it's understandable how Nick stays stuck in this when he has no particular interest. The Wynants just keep popping up, making demands on his time and patience, and Nick is too polite (or too secretly interested) to tell them to go pound sand. And so he keeps being exposed to the next set of lies and twists, and then the cops wanna know what he knows, and they tell him what they know, and he can't help it.