Over lunch, Tom tells Spade about Thursby's record, which indicates that Thursby had been picked up for various offenses from gambling to assault charges. Thursby was also a bodyguard for Dixie Monohan, a gambler in Chicago.
Tom also mentions that they had gotten no useful information from Cairo, and released him after a few hours. Spade then realizes that Cairo had lied about being questioned by the police all night.
Spade heads to his afternoon appointment with District Attorney Bryan, who wants Spade to tell him who killed Thursby.
Spade denies having any knowledge of the murders, but Bryan implies that Spade is either the one behind the deaths or knows the identity of the murderer.
Angry that Bryan and the police are accusing him of being mixed up in the murders, Spade insists that he has nothing to tell him, and storms off in a huff.