The level starts out with Reznov talking to Mason about his father at Stalingrad in Vorkuta. He explains that his father was a musician during the German occupation who was killed by Nazis who found him to be a symbol of defiance. He furthermore says that collaborating with any Nazi is a "betrayal against all of Mother Russia." He then says that Dragovich and Kravchenko were not hindered by such crimes. He then flashes back to the day he was betrayed.
Reznov looks off a snowy cliff with Dimitri Petrenko and Nevski. The group then trudges down the cliff where they meet a younger Dragovich and Kravchenko. Reznov receives his orders to capture Dr. Friedrich Steiner alive, and that he will be shot if he disobeys that order. He and his crew move out on a snow-truck. After a short time, Petrenko asks Reznov why he doesn't trust the two Dragovitch and Kravchenko, to which Reznov will say that at Stalingrad, Dragovich left him outnumbered and never sent reinforcements. He then tells Dimitri that the two men are opportunists, and are not to be trusted. Reznov takes great care to raise his voice when talking of Dragovich and Kravchenko, as their snow truck is right next to his. Reznov returns to Vorkuta and tells Mason that Petrenko was the bravest man he ever knew, and that his heroic feat at Berlin should have made him a hero, but Stalin had little need for heroes.
Reznov flashes back to the mission, where Reznov and his men begin to fight for Steiner. Opposition here is fairly weak, and the player will be armed with a PPSh-41 and a Mosin-Nagant with RGD-33 grenades to deal with them. Russian comrades will burn down buildings to kill all Germans inside. Some Germans will attempt to surrender, but Reznov has no sympathy and tells his soldiers to kill them all anyway. After searching a few buildings for Steiner, the player will be given smoke grenades to mark target for mortars. Here Germans will be standing on bridges with MG42s and Panzershrecks so it is smart to throw smoke grenades on these structures and to pick up a Scoped Mosin-Nagant to eliminate these soldiers, and when you have cleared out some of the earlier buildings and get close to them, to pick up an STG-44, which at this closer range, being an assault rifle, will be very effective for suppressing enemy firing positions, so the player and his comrades can maneuver into the buildings and flank them. This is the most effective tactic for getting you past this area. Eventually, Reznov will fight your way through stiff opposition to Steiner who will insult you and tell you to take him to Dragovich. We now cut to Reznov telling Mason he should have killed Steiner then and there, but his belief in orders stopped this.
Reznov skips ahead in his flashback to outside a Nazi ship where Kravchenko will be executing POWs. Steiner will talk to Dragovich about how the Germans are sworn to protect the Reich, which includes destroying the ship, but Dragovich says to Steiner that there would be no problems. Now Reznov brings his men into the ship while the Dragovitch and Steiner discuss the genius Project Nova and how Washington D.C. and Moscow were to meet a horrible end by the hand of the Fuhrer using V-2 Rockets tipped with Nova-6. However, Berlin had already fell to the Soviets and the SS failed to destroy the Nova-6. The Russian squad and German scientist then reach the last reserve of the gas.
Reznov then says that the victory was short lived, for Dragovich wanted to see the effects of the gas first hand. He then orders Reznov, Nevski, and Tvelin to be thrown in one gas chamber, and Petrenko, Viharev, and Belov to be thrown in another. The latter is to be gassed first. Dragovich unleashes his weapon on Petrenko's chamber, killing everyone inside. Dimitri and his men suffer an agonizing death; caged like animals instead of dying for their country according to Reznov. Before Reznov's chamber can be condemned, British commandos break in to the ship and fire a rocket into the chamber, opening it for Reznov and his men. The soldiers begin to fight their way out, battling through both their traitorous comrades and the British in a two-way battle, watching in horror at the same time as both rogue Russian and British forces futilely fight against each other for Nova-6. Reznov will eventually arm an explosive to a main support beam. The player will be given three minutes to escape the ship. Tvelin is killed at some point during the combat at the end of this towards the end of this mission, but Reznov manages to escape with Nevski having destroyed the gas containers, containing Nova-6.
-An MP-44 is the most useful weapon in this level,due it's great effect at medium-long range,and it's high firepower.Trade your Mosin-Nagan for this.
-Keep the PPSH-41 as there will be also some close quarter combat.
-Be careful when using mortar strike,as if standing too close,you'll be instantly killed due high explosive damage.
-By using mortar strikes,it is possible to destroy the bridge,where player encounters first mounted MG-42.
-One can get a Light Foot achievement by escaping the ship under 45 seconds on Veteran.This requires a lot of skill to acomplish.It is however worth 30 game points on XBOX 360,and a silver medal on PS2 and PS3.
-Even if Tvelin makes it to the rope,he will NOT rappel down it,even if all enemies are eliminated.