Ashley tells you she's got herself in some trouble because she's an addict. Two Eastern European guys tell you that Ashley owes Dimitri Rascalov a lot of money and they want you to kidnap someone called Roman Bellic to partially make up for it.
Once outside, Johnny will call Malc and ask him if he'll help with the mission. Malc is up for it, so make your way to his meeting point by following your GPS.
After the cutscene you'll both be in a car, so now you need to make your way to the gambling place in Broker. Once you arrive, you'll see a short cutscene where the guys grab Roman and stick him in the car. Once you've got him, you need to drive him to Bohan.
Follow the GPS, and as you get about half way there he'll get out of the car and try to escape. Knock him over with your car but don't kill him, then get out and point your gun at him. He'll get back in the car, then you can continue to Bohan. You need to drop off Roman at the factory compound, one which will be familiar if you've played through Niko's story...
- This is a pretty straight forward mission, so no real advice is required.