Follow Khan to find the Dark One | Chapter 20: Quarantine Metro: LL Guide

Last update: 11 May 2016

You, of course need to follow Khan. After you reach the locked door, seize the opportunity and, while Khan is busy talking to the guard at the door, explore the area to the right. In there, you will find another Artyom's diary page next to the gate shown in the screenshot. Return to Khan and take the newly opened passage.

Stop right after you reach the next area because, there are two merchants here (the above screenshot). The one to the left deals in weapon upgrades, whereas the other one deals in ammo, Claymore mines, throwing knives frag grenades and incendiary grenades.

While in this location, also collect the two (free of charge) filters from the shelf to the right and interact with the guitar. You can now continue your walk. The walk's final part is very linear. Soon, the game will start loading the next stage.