In Chapter 13, titled "The Emperor's Gift," Casper Gutman tells Spade about the history of the "black bird," the statuette which he is so anxious to acquire. The gist of his long explanation is that in 1530 Emperor Charles V gave the Knights of Rhodes possession of Malta, Gozo, and Tripoli with the stipulation that they were to give him the annual token payment of one falcon as a sign that Malta was still under the rule of Spain. The Knights of Rhodes were so grateful, and so rich from their spoils as crusaders, that they planned to give the Emperor a golden falcon encrusted with jewels. But the ship carrying the Maltese falcon to Spain was waylaid by the buccaneer called Barbarossa and never reached Spain. Gutman has been trying to track the statuette down for seventeen years, and he knows more about it than any other living person. In fact, he thinks he may be the only person in the world who knows what it is and how much it is worth. An indication of his knowledge of history and languages is contained in on impressive block of dialogue.
"The archives of the Order from the twelfth century on are still at Malta. They are not intact, but what is there holds no less than three"--he held up three fingers--"references that can't be to anything else but this jeweled falcon. In J. Delaville Le Roulx's Les Archives de l'Ordre de Saint-Jean there is a reference to it--oblique to be sure, but a reference still. And the unpublished--because unfinished at the time of his death--supplement of Paoli's Dell' origine ed instituto del sacro militar orgine has a clear and unmistakable statement of the facts I am telling you."
Gutman finally traced the falcon to the home of a Russian general in a Constantinople suburb and offered to buy it, but the general refused to sell it.
"I was afraid this stupid soldier might begin to investigate his property, might chip off some of the enamel. So I sent some--ah--agents to get it. Well, sir, they got it and I haven't got it."
After explaining the history of the Maltese falcon up to the present time, Gutman speculates that the statuette must be worth at least two million dollars. Since the book was published in 1920, two million dollars would be equivalent to at least twenty million in today's dollars.
Gutman's "agents" were Brigid O'Shaughnessy and Joel Cairo. Brigid must have let the general pick her up at some bar, restaurant, or casino and take her home, then got out of his bed while he was asleep and slipped off with the falcon, having no doubt been told by Gutman exactly where to look for it. She ditched Joel Cairo by getting him arrested on a trumped-up bad-check charge and came to San Francisco accompanied by Floyd Thursby. Then she wanted to get rid of Thursby to avoid having to share the spoils from the sale of the falcon with him, so she came to the office of Spade and Archer with a completely false story about trying to save her underage sister from Thursby's clutches.
When Spade is grilling her in his apartment in Chapter 20, titled "If They Hang You," he says:
"You thought Floyd would tackle him and one or the other of them would go down. If Thursby was the one then you were rid of him. If Miles was, then you could see that Floyd was caught and you'd be rid of him. That it?"
"S-something like that."
"And when you found that Thursby didn't mean to tackle him you borrowed the gun and did it yourself."
Gutman's quest for the Maltese falcon ends when Wilmer Cook shoots him dead.