In part 6 of the analysis we observed that the first stage of alchemy's Great Work, the nigredo ("the blackening"), is characterized by chaos. It is also associated with the encounter with one's psychological shadow, melancholia, and putrefaction and decomposition. The scenario in Mann's Collateral is that cab driver Max Durocher experiences four nigredos. The first occurs when hit man Vincent's first victim, Ramone Ayala, falls out of a window down several stories and lands, dead, on the top of Max's cab. This is a chaotic scene, and thus represents a nigredo. Max's second nigredo occurs while Vincent is performing his hit on Sylvester Clarke. While Vincent is in Clarke's condo, Max is sitting outside in his cab waiting, with his hands tied (by Vincent) to the steering wheel. When Max shouts for help, two young hoodlums respond, and one of them steals Vincent's briefcase from the back seat. When Vincent shows up, he shoots the two men dead. There is chaos during the entire sequence of events. Max suffers a panic attack after Vincent's third hit, jazz club owner Daniel Baker, is shot point blank in the head. This scene, too, is chaotic. Finally, there is complete chaos and pandemonium in the nightclub, Club Fever, before, during, and after the execution of gangster Peter Lim.
From Collateral - Max's four nigredos: Top left: Ramone Alaya falls onto the top of Max's taxi after being shot by Vincent. Top right: Max is harangued by some armed hoodlums, who end up being shot by Vincent. Above left: Vincent shoots jazz club owner Daniel Baker, immediately after which Max has a panic attack. Above right: Pandemonium in Club Fever.
Since Max defeats Vincent before Vincent can kill Annie Farrell, his intended fifth and final hit, there are four nigredos being depicted in the movie corresponding to Vincent's four hits.