Call of Duty: Modern Warfare 4 DMZ Operation Fallen Ember Story Mission Walkthrough

In Call of Duty: Modern Warfare 4, Operation Fallen Ember is one of the DMZ story missions. Its setting is the Haneul Nuclear Reactor, a hazardous site on Hajin’s coast carrying THREAT: HIGH. The objectives span several areas: manually retrieve three fuel rods from the submerged reactor pool, decontaminate them in another reactor, eliminate a commander to obtain a key, and take a patrol boat offshore.

Quick answer: Unlock Reactor 01 from the dome roof, pull three fuel rods from the pool, decontaminate them at Reactor 02, kill Commander Colossus for the boat house key, then escort the chopper by boat. Exfil afterward.

Operation Fallen Ember objectives in order

The HUD lists these under “MISSION: OPERATION FALLEN EMBER”. Each one has to clear before the next appears.

#	Objective	Where it happens
1	Reach the Reactor	Haneul Nuclear Reactor
2	Unlock Reactor 01	Damaged dome roof
3	Initialize the First Fuel Rod	Reactor 01 mezzanine console
4	Withdraw the First Fuel Rod	Flooded reactor pool
5	Initialize the Second Fuel Rod	Safety console, reactor pad
6	Withdraw the Second Fuel Rod	Flooded reactor pool
7	Initialize the Third Fuel Rod	Safety console, reactor pad
8	Withdraw the Third Fuel Rod	Flooded reactor pool
9	Decontaminate the First Fuel Rod	Reactor 02
10	Decontaminate the Second Fuel Rod	Reactor 02
11	Decontaminate the Third Fuel Rod	Reactor 02
12	Secure the Warhead	Reactor yard
13	Eliminate Enemy Reinforcements	Reactor yard
14	Loot the Boathouse Key	Reactor yard
15	Raise the Garage Door	Boat house
16	Rendezvous with Chopper	On the water
17	Escort the Chopper Until Safe	On the water

Radiation gear for the Haneul Nuclear Reactor

The briefing card rates Fallen Ember [THREAT ASSESSMENT: EXTREME] and lists three main objectives: Breach the Reactor, Secure the Rods and Extract Decontaminated Rods, with a 25000 cash icon among the rewards. Its Recommended Equipment line reads 3-Plate Armor Vest, Medkit, Gas Mask, Radiation Blockers. Deploy without those and a RECOMMENDED ITEMS warning lists Weapon, 3-Plate Armor Vest, Small Backpack, Medkit, Gas Mask and Radiation Blockers.

The reactor area is lethal without protection. Once you get close, the SK Radiation Alert System warns you with “Danger: Lethal radiation levels detected”. Bring or loot the following; radiation gear turns up in lockers and bags around the reactor:

RADIATION BLOCKERS, a consumable that reads “Mitigates Effects Of Radiation” and lasts 60s
A GAS MASK, or the epic DURABLE GAS MASK
Armor plates for the long fights
A HAZMAT SUIT (LEGENDARY, GEAR) hanging on the wall of the Reactor 01 control room, next to the console that starts the rod release
An ammo or armor box for the defensive stretches

Getting into Reactor 01

You infil on Expressway No. 1. A military compound, Compound Delta (THREAT: MEDIUM), sits near the road on the way in. The side op tracker counts your progress as a percentage (Clear the Military Compound 81% partway through), and clearing it completes the side op CLEAR THE MILITARY COMPOUND, which counts toward your side op payout later. Keep heading for the reactor until the SOUTH KOREA / HANEUL NUCLEAR REACTOR / THREAT: HIGH banner appears.

Reactor 01’s ground-level doors won’t open initially. Head for the marker at the lockdown override atop the damaged dome. Reach the roof via the exterior ladder, then ride the ascender line. Activating the override advances the task to initializing the first fuel rod.

Haneul Nuclear Reactor point of interest card rated THREAT: HIGH, showing a foggy reactor interior with a sphere — The Haneul Nuclear Reactor card, rated THREAT: HIGH, shows the fog-filled reactor interior. Image: Activision

How to pull the three fuel rods

The consoles start each release, but they don’t hand you the rod. You have to dive into the flooded reactor pool and take each one out yourself.

Enter through the broken dome and take the stairs down to the Reactor 01 catwalk. Use the control console on the mezzanine. The screen reads “CONTROL ARM SEQUENCE INITIALIZED – PLEASE WAIT.”

Drop from the catwalk into the pool. Circular fuel-rod hatches cover the floor, with letters and numbers running around the perimeter.

Dive to the open hatch, then select “COLLECT FUEL ROD” to retrieve the first rod.

For the second rod, the game shows “PLEASE CONFIRM NEXT MANUAL RELEASE AT SAFETY CONSOLE.” Confirm the release at the safety console, then initialize at the reactor pad. This opens several rod hatches at once.

Check the open hatches one at a time. A wrong one shows “INCORRECT ROD”. You can open closed hatches with “OPEN FUEL ROD CONTAINER”. Keep searching until you can collect the rod. In a squad, keep one player at the safety console: it names the correct container by the letter and number painted on the pool floor, so the diver can swim straight there instead of trying hatches one by one.

Repeat the safety console confirmation, the pad initialization and the hatch search for the third rod. Once it’s out, the game reads “ALL ELIGIBLE FUEL RODS REMOVED. HAVE A NICE DAY.”

While you’re searching, reinforcements take positions on the catwalks above the pool. Surface and eliminate them before diving back in.

Lieutenant Chemist at Reactor 01

Around the time you take the first rod, LIEUTENANT CHEMIST appears in the Reactor 01 corridors with regular soldiers alongside him. Fight from doorway cover and use aimed rifle fire.

Killing him triggers SIDE OP COMPLETE / KILL CHEMIST. He drops CHEMIST’S DOG TAG and a W.M.D. MANIFEST. The manifest is an epic valuable worth 5000, and its description reads “Can be extracted and sold in the FOB for cash.”

While you carry his dog tags, enemies can see your position until you extract them.

Decontaminating the fuel rods at Reactor 02

Take all three rods to Reactor 02 and interact with the processing station using “PROCESS RADIOACTIVE MATERIAL”. A DECONTAMINATION bar starts filling, and the text counts up as each rod goes through, from “CONTAMINATED MATERIAL DETECTED – COMMENCING HAZARD MITIGATION 2/3” to 3/3.

Soldiers push into the room while the bar runs, so you’ll need to defend it. Each rod that finishes turns into Depleted Uranium – Clean in your inventory.

While the rods process, look around the flooded floor of Reactor 02. A REACTOR DRC LOCKER sits underwater there. With its key, the prompt reads REACTOR DRC LOCKER – UNLOCK, and it opens into an ELITE WEAPONS LOCKER; one held an ISO NIGHTSHADE (ULTRA SMG, $9,100).

Secure the Warhead: Killing Commander Colossus

Use the marker to retrace your route through Reactor 01, then exit via the blast door into the mist-covered reactor yard. In the yard the objective first reads Eliminate Enemy Reinforcements as armored soldiers push in, and once they are down it switches to Loot the Boathouse Key. COMMANDER COLOSSUS patrols there with infantry; at close quarters, his heavy automatic fire can drop you quickly.

DMZ Commanders panel showing a tank and the armored Colossus heavy — The Commanders panel shows a tank and the armored Colossus heavy you fight in the reactor yard. Image: Activision

One approach that works is to retreat, use the yellow ladder to reach the roof beside the yard, and have your squad engage him from above with scoped rifles. His death yields the HANEUL BOAT HOUSE key; collecting it moves the objective forward.

Boat house and chopper escort

Go to the green corrugated boat house next to the yard. Use the key on its door until “DOOR UNLOCKED” appears.

Use “OPEN DOOR” on the panel beside the shutter to raise the garage door.

Get aboard the armored patrol boat inside, then pilot it onto the water. Follow the marker through the South Korean Border Zone and Shoreline toward Songdo Wharf, whose threat rating is THREAT: LOW.

Remain with the chopper until Escort the Chopper Until Safe is marked complete. The mission wraps up out on the water.

How the DMZ story ends

In early access, Operation Fallen Ember sits alone at the top of the story mission tree, so this boat run is where the DMZ story currently ends. Partway along, the patrol boat pulls alongside a station at the Songdo Wharf pier that reads “REFUELING AND REPAIRING…”. Once Escort the Chopper Until Safe is up and you reach open water off the South Korean Shoreline, a bright flash lights the horizon, a “DDOS DETECTED!” alarm flashes and “VEHICLE DISABLED” appears on the boat. A nuclear blast then rises in the distance, and MISSION COMPLETE / STORY MISSION appears over the mushroom cloud.

No cutscene plays and no credits roll. You keep control of your operator with the cloud still on the horizon, and the match carries on until you exfil.

Exfil and Operation Fallen Ember payouts

The patrol boat is the quickest way out: stay aboard, steer to Songdo Pier at Songdo Wharf and walk to the green smoke on the pier. Use CALL EXFIL HELICOPTER there and hold the pier; the chopper lands in under a minute, and EXFIL DEPARTING starts once your squad is aboard. If your squad is wiped out before then, FAILED TO EXFIL / MISSING IN ACTION appears, but the mission payouts remain listed in the EXTRACTION SUMMARY.

Songdo Wharf point of interest card rated THREAT: LOW, showing a beach, pier and docked boats — Songdo Wharf, rated THREAT: LOW, has a beach, a pier and docked boats along the shore. Image: Activision

The pier is not the only option after the blast. The green smoke exfil near Wolves Stadium (THREAT: LOW) also works: after the exfil request there, the radio reports “Orion 6-1 is inbound”, and the chopper leaves with EXFIL DEPARTING.

Extraction Summary line	Cash
1 Story Mission Payout	5,000
2 Side Ops Payout	1,000
1 First Lieutenant Takedowns	10,000
Banked cash	16,000

The two side ops are CLEAR THE MILITARY COMPOUND and KILL CHEMIST, and the lieutenant takedown is the Chemist kill. Together with the story payout, that adds up to 16,000 in banked cash.