FAQ

Since Grocer killed the man that Martin was trying to protect in the opening scene of the film, Grocer thought it might be a good idea to form an underground union of sorts made up of himself & several other assassins who were all clamoring for work around the world after they'd left their respective organizations. Martin worked for several years for the CIA and went independent. It appears that Grocer had as well. As Grocer says, the guild would help them prevent "embarrassing overlap" like the assassination that happened a short time before: Martin shot and killed the cyclist who was going to shoot the man coming out of the hotel. Grocer then showed up and killed the man Martin was protecting.

Grocer's motivation in asking Martin to join is probably that he knows that Martin is an effective contract killer and would be a great benefit to the guild. However, Martin dislikes the idea of working for anyone but himself and especially doesn't want to work for Grocer. He also mentions during the cafe scene when talking to Grocer that "bad things start happening" when people like them join forces. Martin might have some experience in that area but he might also know about the experiences of peers that ended badly -- they may have turned on each other in a grab for power or money.

Out of petty revenge, Grocer calls Lardner and his partner and informs them that Martin will be targeting Debi's father in Detroit & they're sent out to catch Martin in the act and kill him as an enemy of the state.

He's a member of the Basque organization who has been contracted by another of Martin's clients to kill Martin.

Some months before the story opens, Martin had been contracted by one of his clients to kill someone for them. While he was trying to complete the contract, a dog, that the mark(s) had borrowed from Martin's clients was accidentally killed while retrieving a stick of dynamite they'd been using to flush game while hunting. The client blamed Martin for the dog's death and put a contract on him using LaPoubelle.