Can you explain chapter 18 in detail?

In Chapter 18, Malcolm moves to Harlem and begins spending time at a bar called Small's Paradise. Here he meets a man called “Sammy the Pimp” (245). Sammy calls Malcolm “Detroit Red” (251) because he is from Michigan, and introduces him to West Indian Archie, the man in charge of the numbers game in Harlem. Malcolm overhears some men in the bar talking about Marcus Garvey. They attempt to engage him in conversation, but he rebuffs them.