Dying Light 2 The First Biomarker Dr. Katsumi Safe Code Answer

There are tons of side quests in Dying Light 2, and some appear later than others, while some disappear once you reach a certain point in the campaign. One of those side quests, called “The First Biomarker,” is relatively straightforward, except for a pesky safe code riddle from Dr. Katsumi that keeps you from the objective.

When you start The First biomarker, you’re tasked by an NPC to return to Saint Joseph Hospital from earlier in the campaign and pick up a biomarker with … unique properties. But you’ll need to know the safe code answer to get it. 

The NPC will tell you the riddle, and it’s also written on the safe code if you inspect it in your collectibles tab in the player menu. The riddles go as such:

• What [number] 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?

While the riddle from Dr. Katsumi can take some time to decipher, the First Biomarker safe code is: 9.7.3. 

You’ll get an Inhibitor and a collectible (Confidential Notice to GRE Personnel) for completing the side quest. This is the only Inhibitor linked to a side quest, so be sure to grab it if you’re going after the Fit as a Fiddle or Iron Heart trophies and achievements. 

And there you have it: the answer to the First Biomarker safe code riddle left by Dr. Katsumi. If you’re wondering what the approximate number of pi is for another safe code, we’ve got the answer for that right here. Looking for more tips? Head over to our Dying Light 2 guides page.