Hostile Negotiation

Hostile Negotiation is a mission in Grand Theft Auto IV triggered after a phone call. Niko saves Roman after he is kidnapped by Dimitri Rascalov.

Description
Provided the player has completed Photo Shoot, Have a Heart, and Roman's Sorrow, Niko Bellic 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 (like a grenade). Fire it to show the goons you mean business!

Walkthrough
Grab the AK-47 outside of the warehouse as extreme firepower is needed, especially in the warehouse which is full of cover, and guards. At first, the thugs will not notice you. Using the element of surprise, take a burst of shots at a group of enemies and aim for the heads. Take out every guard from the first floor while in cover. Some are in cover too, so go inside and finish them. Remember to always take cover, and try to kill any guards on upper floors too. 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. It is possible to shoot the fuel tanks that are out of the crate, causing a large scale explosion, ending any nearby enemies. There is a guard just before the stairs to the third floor, who will drop some well needed armour once killed, should you need it.

Make your way to the third floor and shoot the goons on the roof that become visible, one shot is enough to send them sliding and the fall will kill them. The last guard has heavy armor and will need several shots to kill. Walk into the last room after he is dead and a cutscene shows Roman Bellic and an unknown kidnapper emerge from the back of the room. The kidnapper has Roman in a chokeheld, with a gun to his head. Take cover, and quickly free aim at the killer's head. If you take too long, the kidnapper will fire at Niko, and eventually execute Roman. Use any gun, but the pistol is the safest, and shoot the kidnapper.

Once Roman Bellic is freed, a scene will play where Roman will thank Niko for his rescue. Follow Roman and get into the nearby Bobcat, and drive him to your safehouse in Bohan. Make sure the truck doesn't hit any explosive barrels near the warehouse as this will blow you 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 East, Algonquin to hide from Dimitri. 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.

Trivia

 * The events in Hostile Negotiation mark one of the few links between the GTA IV storyline and its episodic counterparts. In this example, the events shortly prior to this mission are played through the perspective of Johnny Klebitz in The Lost and Damned episodic content. It is revealed that Johnny Klebitz kidnapped Roman because Ashley owed Dimitri's men a favor after acquiring a large debt. This side of the kidnap, the mission name is Roman's Holiday, and has Johnny and Malc kidnapping Roman after gambling at his usual spot and then taking him to the warehouse in Bohan's Industrial District.
 * This event is also briefly referenced in the original GTA IV storyline, in the form of Roman sending Niko a text explaining how a biker kidnapped him.
 * Once you receive the picture message of Roman from Dimitri, Niko will talk furiously about him, saying; "You've crossed the line, Dimitri"!
 * If you try to land on the roof of the warehouse with a helicopter, you will be shot by two guys standing on the roof with rocket launchers.
 * The staircase where you will go down (after you have rescued Roman) can actually be used to speed up the mission (on the part when you are about to save him); instead of going to the yellow marker, go upstairs, then you will hear the dialogue of Roman and the captor (because you are already at the same floor with them, only that you are outside the warehouse). Most of the henchmen from inside the building will take aggressive action and go up the stairs as well, making them prone to gunfire and, therefore, easier to kill (they have no cover). So it makes the mission a killing spree instead of a takedown.
 * An interesting phone call can take place if Niko calls Dimitri after he receives the photo of Roman. Niko will furiously describe how he will cut off Dimitri's face, and hang it on his wall to remind himself of what a treacherous, cheating scumbag looks like, then saying "Goodbye, friend." Niko calls him "friend" as a reference to Dimitri ending his own text messages to Niko with "Your friend, Dimitri."
 * There is a Carbine Rifle in one of the rooms on the bottom floor of the warehouse.
 * If you killed Ivan Bytchkov in the mission 'Ivan The Not So Terrible', a Russian-American goon will shout 'Say hello to Ivan the Terrible for me!" before being shot by Niko, possibly explaining Ivan had more connections with the Russian Mafia than previously known about.
 * If you have Dwayne's special ability you can call him and he will send two of his guys round to help.

Deaths

 * Roman's Kidnapper without a released name - The kidnapper was executed when he was threatening Roman at gunpoint.
 * A ton of Russian goons - Over 30 of Dimitri Rascalov's goons were supposed to kill Niko Bellic and Roman Bellic however failed when Niko came to rescue Roman.