You have to beat Fat Joe as Crack in "Club Murder". Just use the cage walls to make short work of him.
D-Mob gives you the medallion with Blaze by his side. The limo gets shot by Trejo, hitting D-Mob in the process. You chase Trejo into the Subway.
The Subway can be a good thing or a bad thing. The good news is in every intervals, you can throw him into it to get hit. The bad news is that things can go easily wrong if you try to survive the danger of being KO'd by subway, weapon and walls made of steal.
You came back to the injured D-Mob. But the police cam so you and Blaze escape the incident. You persisted to vengeance against Crow but Blaze stops and tells you to continue fighting more and more clubs from Crow. And yes, Doc has finally woken up to take part in your cause.