There has never been any private detective as cool as Sam Spade, and I mean that most sincerely. Dashiell Hammett based him on his own experiences as a Pinkerton detective, but unlike his other fictional detective, the nameless Continental Op, Spade isn’t just doing his job, he is the job. Hammett stated once that Spade was the detective that every detective wishes that he could be and occasionally approaches, on their best day. If you’re asymptotically approaching awesome then you’re just catching up to where Spade already is. He’s that kind of guy.
It’s also worth pointing out that you might not actually want to be him, since Spade is also really low-down and mean. In fact he is a colossal prick and not in that “jerk with a heart of gold” way. When his partner gets killed, his first action the next business day is to call the sign painter to get the guy’s name off his door – he reveals that he thought the guy was a dumb son of a bitch and was just waiting for their annual partnership agreement to expire so he could kick him out anyway. In addition, he was sleeping with his partner’s wife, maybe just to spite him, since Spade doesn’t seem to think very highly of her either.
The partner got killed helping out a new client, who in fine pulp detective tradition is a beautiful lady who walked through the door with a story of trouble. Which, of course, Spade and his partner didn’t believe, but they did believe in her cash, so they were willing to go with it. The name she originally gives is a fake; later she claims to be one Brigid O’Shaughnessy, but I don’t know if we’re supposed to believe that either. Spade doesn’t trust her and treats her pretty badly throughout, but she did get his partner killed. That doesn’t stop him from sleeping with her too, of course. But then whatever affection he might have for her also doesn’t stop him from strip searching her when he thinks she might have stolen some money from him and, towards the end, throwing her to the cops to face a capital murder charge. When she pleads for him not to, he seems genuinely surprised that she believes his personal feelings are going to have any bearing on his actions.
Along with O’Shaughnessy come a succession of oddballs and goons, including Floyd Thursby (killed offstage), the morbidly obese Gutman with his henchman Wilmer, and the unfortunate Joel Cairo, a man of undefinable Mediterranean ancestry who the narrative takes every opportunity to insult and degrade for his homosexuality. I guess in the movie version they couldn’t just explicitly come out and call him a “fairy” like the book did because of the Hays code, so they just cast professional weirdo (and real life all-around gentleman) Peter Lorre and gave him a perfumed handkerchief and let it go at that. Subtlety was definitely better in this instance. I mean, Cairo is a bad dude because of all the legitimately bad stuff he does, like murder and arson, his sexual preferences aren’t really relevant to that. It's rough reading for a modern audience, really.
Anyhow. This bunch of misfits is after the Maltese Falcon, which is a priceless, jewel-encrusted artifact. It could have just as easily been a suitcase full of money or a delicious cake recipe; all that really matters is that Gutman and the rest of these jerks want it. Gutman thinks that Spade knows where it can be found, since O’Shaughnessy and Thursby had stolen from him what he’d previously stolen from some Russian general who allegedly didn’t know what he had. But actually this unseen Russian dude is smarter than the whole gang of thieves from the very beginning. As Spade says, “Jesus God, have you people never stolen anything before?” And this is when he’s still trying to ingratiate himself with them. None of this motley crew seem to know what they are doing with regards to crime, only Gutman seems to have a reasonable fence for this treasure anyway, and their ineptitude would be funny, if it weren’t for all the murders. As it is, it’s still pretty funny.
Spade doesn’t personally kill anyone in this book, and doesn’t even carry a gun, for that matter. He does beat up a couple of people and take their guns away, though in one case it’s Cairo and probably wasn’t all that tough. In fact, that’s one of the best scenes – Cairo comes in, pulls a gun on Spade, and demands to search his office. Commence beating and gun-grabbing. After Cairo regains consciousness, they have a brief discussion and Spade gives him his gun back, which is a bad idea since Cairo then steps back a little farther, and searches the office at gunpoint for real.
The whole book is like that. These crazy people are going around doing nonsensical things, and Spade is always a little bit ahead of them. Towards the conclusion he gives a couple of hints that he might not actually be as bad as he’s making out, but I don’t know if it’s true or even if he believes that it’s true. For the ultimate detective, at the end it’s all about style.