When Aiden first arrives in Villedor, the residents of the normally peaceful Bazaar almost execute him publicly because he wasn’t wearing a biomarker. Because, in the remains of the new world, every citizen must strictly wear one for their survival and the safety of those around them.

With Hakon’s help, Aiden retrieves his own biomarker, which is crucial to fighting off his infection. A biomarker monitors its wearer’s vital signs and warns them about the current stage of their infection. 

In-game, your biomarker watches your immunity at night or when you enter a dark area. Knowing how much time you have left before turning gives you ample opportunities to use your immunity boosters or run towards a UV light.

Throughout your adventure, you might come across a man who claims that he invented the very first biomarker. You can listen to his story and accept his quest. In doing so, he will give you a note containing the first biomarker safe code and directions to the safe.

Where to Find the First Biomarker Quest

The First Biomarker quest giver is found on the trading post settlement to the west of Trinity. It’s to the west of the Alder windmill and the south of Saint Joseph Hospital.

There you’ll find an NPC named McGregor. He claims to have invented the very first biomarker and that the original prototype is vastly superior to the latest and ubiquitous version.

One of his claims is that the original device grants super strength to its wearer. But he also admits that there were other unintended side effects.

Because of its instability, Dr. Katsumi, then head of the GRE, confiscated the device and locked it in the safe. McGregor asks you to find and crack the first biomarker safe inside Saint Joseph Hospital.

You can track quests in Dying Light 2 to give you a waypoint on where to go.

The First Biomarker Safe Code

McGregor gives you a note written by Dr. Katsumi. It is a riddle that contains the first biomarker safe code. The riddle reads:

“What becomes smaller when you turn it upside down?”

“An odd number – take away a letter and it becomes even.”

“A little girl goes to the store and buys one dozen eggs. As she is going home, all but three eggs break. How many eggs are left unbroken?”

The answer to the riddle and the first biomarker safe code is 973.

Now that you have the answer, head over to Saint Joseph Hospital.

Keep running to the west of the trading post. Once you jump down from the roof and onto a lower platform, look to the green walls on your right.

Hop onto the street light and jump on the edge of the building. Then, point your camera on the edge of the next floor, and hold your jump button.

If that’s too advanced for you, there’s also the way it’s supposed to be done.

Go down to street level and keep circling Saint Joseph Hospital until you find an exposed wall. You can climb these walls in Dying Light 2. Hop on the ladder next to it and ascend to the roof.

Find the broken Saint Joseph Medical Center sign. The first biomarker safe is close to it. Before you go, there’s a rooftop garden nearby with valuable honey and chamomile. 

Walk under the entrance, then look at the broken panel with police tape draped on the edge. Jump inside the office, and the first biomarker safe should be on the shelf behind the tables.

Enter the code and retrieve the first biomarker.

For some reason, Aiden will wear the biomarker. So naturally, your vision will become blurry as soon as that happens. And zombies suddenly choose this time to ambush you.

Attack them, and they’ll all die with just one hit. So it seems that McGregor wasn’t kidding when he said it endows the user with enhanced strength. 

To get back quickly, use the zipline found on the side of the makeshift shack. Doing so will bring you on top of the buildings on the other side of the street.

Return the first biomarker to McGregor. He’ll generously reward you an inhibitor and a confidential notice to GRE personnel collectible. This is one of the few quests where you can find inhibitors, a great reward for a relatively easy quest.