Completing GRE quarantine buildings is one of the most difficult nighttime activities in Dying Light 2. You have to find four inhibitors in three floors overflowing with zombies and hazards. On top of that, you have one night to clear it before all the stronger infected come crawling back.

One wrong step and you can alert a whole floor of zombies, before you know it you’re surrounded by virals and infected. Whether through stealth or through brute force, there’s no easy way to do it.

Even though completing GRE quarantine buildings are an optional challenge, the rewards and loot you can get from it are invaluable. Aside from the legendary inhibitors which can boost your stats, there are also rare components and powerful equipment.

It is a daunting task, and it shouldn’t be the first activity you aim to complete. But when you’re prepared in experience, items, and gear, here’s how to complete GRE quarantine buildings and where to find them.

How to Find GRE Quarantine Zones

There are 6 GRE quarantine buildings found in the game. It’s hard to miss it since they are tall buildings entirely covered in a green tarp. A few signs also surround the building, warning citizens not to enter the area.

If you spot one, make sure to tag it using your binoculars. Afterward, you can gather more information on how to complete GRE quarantine buildings by viewing it on the map menu. There you could find the name of the building, a bit of backstory, and most importantly, the recommended level.

Once you’re ready to access the GRE quarantine building, you have to climb to the roof to enter it. Typically, use the scaffolding surrounding the area to scale the building. Alternatively, go to a nearby high area and use your paraglider to reach the roof.

There’s a containment area that you can open with your GRE access key. Descend the ladder to start this difficult optional challenge.

GRE Quarantine Building Locations

Here are the names and locations of all GRE quarantine buildings, along with what districts they are located at.

The first two GRE quarantine buildings are located in Old Villedor.

The Center for Stage IV THV Study is located in the Houndfield district. It is to the northeast of Cherry windmill.

The THV Genomics Center is found in the Horseshoe district. You can find it on the east of the Horseshoe Water Tower, an important story location.

The next four GRE quarantine buildings are found in the next area of the game, Central Loop.

The GRE Vaccine Lab is located Downtown. West of Metro Downtown Court. You can easily reach this building by taking the shortcut to the top of Metro Downtown Court that Lawan showed you after the Let’s Waltz questline.

The HV-GenMod Development Center is located in the Saint Paul Island district. West of the Saint Paul Electricity Station and north of the Chapel of Resurrection landmark.

The THV Advanced Care building is found on Lower Dam Ayre. North of Metro South Loop and west of South Loop Radio Tower.

Lastly, the GRE Experimental Research building is found in The Wharf. It is to the southwest of the Magnolia windmill.

Preparing for the Dark Zone

To successfully complete GRE quarantine buildings, you must prepare for the worst.

It is best to enter the building during nighttime because the stronger special infected, like the Volatile, is outside during that phase. Enter as soon as night starts because you don’t want to get caught in an awkward position when all the infected come crawling back inside. The enemies will respawn when the sun comes back up, and the stronger infected will come back.

There’s nothing worse in Dying Light 2 than a Volatile in a closed area.

You want to collect UV shrooms and immunity boosters to stave off the infection. However, since you’re inside a dark zone, your immunity will slowly deplete, and there are no UV lamps inside between the top and bottom floors. There are also hazardous chemicals that will rapidly drain your immunity gauge.

Ranger gear will also be helpful for the journey. Armor classified for the ranger class has important stats for stealth and ranged gameplay. Recognition time, which lowers the time before zombies are aware of your presence, and boosted survival sense, which buffs the range and cooldown of survival sense, is vital to efficient stealth. Raised ranged damage is also significant to ensure a clean headshot with your bow.

Speaking of your bow, craft some arrows so you can deal with the wandering infected on each floor. The special arrows could also help when the situation turns for the worse. The electric arrows really shine in these closed spaces because they can arc from foe to foe.

Noisemakers like decoys can come in handy when there are multiple zombies blocking your path. Simply throw one away from where you want to go and sneak past them. Make sure that you don’t need to go back since they’ll be awake and alert, meaning they will have an easier time spotting you.

Assume the worst and prepare for a situation when you break your stealth. After all, one awkward takedown or a zombie in the wrong place could alert the whole floor. Craft upgraded Molotovs and explosives to deal with the horde.

Remember you’re in a closed area, which could be to your advantage. Don’t hesitate to chuck grenades if the situation calls for it. No reinforcements are going to come running towards the noise.

There will also be a lot of lockpicking involved to complete GRE quarantine buildings. If you’re not the best at picking a lock under pressure, you could upgrade your lockpick at the nearest craftmaster. Doing so will allow you to consume a lockpick to force the lock open, letting you slip through the floor faster.

When it comes to your perks, Stealth Movement speeds up your mobility while sneaking. This perk allows you to glide from hiding space to hiding space without alerting the sleeping biters.

Stab and especially Stab Followup is extremely useful in thinning down biters who are in your way. Using these two perks consecutively lets you quickly take down two enemies simultaneously.

Windmill would be a must-have perk if you woke up the whole floor. It releases a devastating attack in an area around you. And you will need this sweeping attack when you’re surrounded from all sides.

Don’t forget to bring your most powerful weapon and install weapon mods in it. Fire and shock are choice elements since they can cut down the horde. Bleed is also sound if you have a hard time dealing with the stronger infected on the final floor.

Tips and Tricks for GRE Quarantine Buildings

As mentioned in the last segment, go as soon as night comes. You’re going to need as much time to sneak around the GRE quarantine facility. Facing the looming threat of morning isn’t going to help you make rational and careful decisions.

Either sleep in a nearby bed to fast forward to nighttime or patiently wait it out. Naturally, you want to be ready to descend as soon the sun falls.

To complete GRE quarantine buildings, you have to go down three floors and collect all four inhibitors. There are two inhibitors each for the first two floors, while the last floor contains the last two in a locked GRE cache.

Before entering each floor, don’t forget to open the doors for the emergency exit. These are locked from the inside and can only be unlocked from the current floor. Use these as a last resort if the situation is too dangerous for you to continue and you need to leave immediately.

Ready? Follow the big yellow tube on each floor for the most direct route to the next floor. But remember that the rare loot is found in dangerous areas like ruined areas with spilled chemicals and on the research tables on the corners of the room. 

You can use your GRE access key indicator to find inhibitors in Dying Light 2. It will give you a verbal notification if you’re within 50 meters of a cache containing an inhibitor. But if you’re within 10 meters, you can spot the cache using your survival sense.

The inhibitor cache will always be behind a locked door in GRE quarantine buildings. Silently takedown the nearby zombies if you need more time to open with a lockpick. There’s usually a collectible that you can grab next to it. 

Although there are an overwhelming amount of zombies, most of them will be asleep. However, there will always be at least one roaming zombie who will make sneaking much more difficult. Prioritize taking down this zombie first, so you have more time to navigate the area.

Do your best to take it down with one hit. Either sneak from cover to cover before using a melee takedown or striking an accurate headshot with your arrow. If you kill it with one hit, it will alert the nearby sleeping beauties.

Make sure that you enter the GRE quarantine building at the appropriate level. If you’re below the suggested level your takedowns won’t kill biters in one hit. Instead, they’ll turn and grab you, also alerting nearby zombies.

Keep your flashlight off at all times to avoid waking up the biters. GRE quarantine research facilities are dimly lit enough for you to make your way through. It’s okay to turn on your flashlight for brief instances if you need guidance.

GRE quarantine zones will have a lot of valuable loot scattered around. Keep in mind that you don’t need to take these to progress. As much as possible, focus on your goal to find the inhibitor caches plus the occasional GRE cache and the expensive crystal core.

Attempt your best efforts to retrieve these precious items but don’t waste too much time on them. After all, there will be many more opportunities to loot rare components in Dying Light 2 without all the risk involved. 

The first two floors can be finished with stealth, but no one said it’s a requirement. If you accidentally alerted the floor, it’s time to bring out your firepower and kill everything in sight. 

Slowly make your way back to the entrance while killing fast-moving Virals and throwing explosives at the swarm. If you need some time to breathe, throw a UV light to stall the Virals and climb up the emergency exit, giving you time to heal.

It’s important to not let them surround you and let the zombies approach from one angle. You can brute force your way to complete GRE quarantine buildings with enough resources.

Personally, I’m fully decked out with tank gear and a two-handed weapon. GRE quarantine zones are opportunities for me to show off my giant sword. 

The first two floors can be completed with stealth, but the third floor presents a more brutal expectation.

You can still sneak through the third and final floor. I’ve done it once or twice with a well-placed decoy. But you have to assume you’ll fight because it is a much more open area without good hiding spots.

There’s usually a large power core in the center of the floor where you can stay. From here, you can take your time sniping zombies with your arrow. You can kick them down if they try to climb up.

There’s always a special infected waiting for you on the bottom, like the brutish Goon or the agile Banshee. Taking down the common infected and virals near it lets you focus more on your combat encounter with it.

This is why it’s useful to have a few throwables prepared. There are a lot of zombies in this room, and you can become overwhelmed in an instant. Use your parkour skills to reposition yourself in the higher ground or through a doorway where the zombies could funnel towards you.

With all the zombies clear, you can take your time to loot the final floor and claim the last two inhibitors. From there, you can unlock the bottom containment area with a GRE access key to walk out of the building. 

Alternatively, if you reach the final floor and can’t deal with the special infected, or it’s morning, and there’s a Volatile down there. Run towards the door and exit the building. 

Find a nearby bed and reset the night. Then, you can use the unlocked door as a shortcut to the bottom floor. The locked door containing the inhibitor cache is always next to the containment area anyway, which means you can easily sneak back inside.

Rewards for Completing a GRE Quarantine Building

Completing GRE quarantine buildings gives you the four inhibitors from the caches. Inhibitors are invaluable in Dying Light 2 since you use them to increase your stamina, health, and immunity.

There’s also an abundant amount of rare materials you can scavenge from the area and chests. You can also find high leveled gear and weapons.

Like any other nighttime activity, you’ll also receive a considerable amount of parkour and combat points.

After looting all 24 inhibitors from all GRE quarantine buildings, you’ll get the “Can’t You Read the Signs” achievement.