The next section of the Metro Exodus Guide is a walkthrough of the metro stage. Artyom and Miller enter the city to find medicines for Anna.
Go ahead and you'll quickly come across some enemies - mutants. Shoot them and keep an eye on the health bar as their attacks are quite powerful. Then follow your companion to the next room. Use your box to unlock further passage.
Continue with Miller. After some time, you will reach the flooded corridor - go further. If you get lost, follow Anna's father, or look for green mushrooms that indicate the way forward. Go further ahead and you'll fall through the grate down - fortunately, your companion will help you get back up.
Proceed forward until Miller uses the red flare. A new wave of mutants will emerge from underneath the big pile of corpses - eliminate the threat. After all, go to the knob next to it and turn it to move on.
After a short walk, you will reach the snow-covered room. Go up to the manhole and remove the cover from it. The boy will be there. Miller will help you jump to the other side, and you will have to chase the boy.
This fragment is quite simple. Chase him passing the obstacles until you reach the room where you have to look for the boy. He's in a metal barrel - open it and you will see a short scene.