Hostile Negotiation is a mission in GTA IV.
After Photo Shoot, Niko will get a call from Mallorie, saying that Roman has been kidnapped. Dimitri Rascalov (Niko's nemesis) sends a violent picture of Roman held at gunpoint which Niko mutters at. Head over to the warehouse in Bohan and run to the back. Use the element of surprise and don't use any guns on your way to the yellow marker. Pick up the assault rifle near the yellow marker.
Niko will automatically gain cover and spot his cousin Roman on the very top floor of the giant warehouse. Using the element of surprise, change to a weapon that you think can take out a bunch of people at once. Fire it to show the goons you mean business!
Take out every guard from the first floor while in cover. Some are in cover too, so go inside and finish them. Walk up the stairs to the second floor and look to your right. About five goons are hiding. Shoot them and use their cover to kill the rest of the people on the second floor. Make your way to the third floor and shoot the goons on the roof that become visible. Kill the last of the ones inside and walk up to the room that Roman is being held in.
Once Roman Bellic is freed, you will see a scene where the goon is executed and Roman is freed and injured. Get into the nearby pickup truck with Roman and drive him to your safehouse in Bohan. Make sure the pickup truck doesn't hit any explosive barrels near the warehouse as this will blow it up.
After this Roman reveals his gambling addiction and also a few in-game hours after you drop Roman off, he will call you to inform that he has purchased a new penthouse in Middle Park, Algonquin to hide from Rascalov. You can now use that as your safehouse. Also because Roman is making a great deal of money, he's bought a new fleet of cabs for his Cab Service. Instead of the rusty old Esperantos, it's now black Cavalcades. However, he didn't hire any new taxi drivers (which means you're stuck with stupid Mohammad!)
- In The Lost and Damned episodic content it's revealed that Johnny Klebitz kidnapped Roman because Ashley owed Dimitri's men a favour after acquiring a large debt. This side of the kidnap, Roman's Holiday has Johnny and Malc kidnapping Roman after gambling at his usual spot and then taking him to the warehouse in Bohan.
- If you try to land on the roof of the warehouse with a helicopter, you will be shot at by two guys standing on the roof with rocket launchers.