Developer Pack (Developer Pack DLC Level)

The Developer Pack is a level in the Metro: Last Light DLC of the same name that includes the AI Arena, the Metro Museum and the Shooting Gallery.

Overview
The level starts with the unknown player ascending an elevator. On the way, through a window you will see a strange old woman staring at you. When you arrive at your destination, you will discover she has somehow arrived before you. If you turn your back on her and walk away, an ominous sound will play (this sound is heard multiple times in multiple locations throughout the main campaign) and she will be in a different location doing something strange such as: sitting on an invisible chair; weeping on the ground; holding her broom as a gun; sweeping; dancing seductively; etc. There are two doors here, the left leading to the Shooting Gallery and the AI Arena, and the right to the Museum.

Trivia

 * In the entrance with the old woman, there are numerous rats that can be shot similar to the Venice shooting range.
 * It is a mystery who the old woman is meant to be, if anyone. Likely, it is just to make the Developer Pack seem a bit creepier. She can be shot with Helsing arrows and throwing knives that will stick in her body. When she disappears and respawns somewhere else, they will still be lodged in her.
 * Resist the urge to smash any lamps found in the level, as they will not respawn unless you restart the level from the beginning, though there is ample light anyway.
 * If you are killed by enemies in the AI Arena or Shooting Gallery, you will simply respawn, with nothing lost. However, if you kill yourself (e.g: Grenades, fire etc.) you will die and the level retry screen will pop up. Any progress will be lost if you have not saved it, so do so regularly, just as a precaution.
 * Undead soldiers appear in whole last two levels of challenge modes. Undead in Shooting Gallery have weak HP, but in AI Arena challenge mode their HP is quite large so it is recommended that you avoid them as well as you can.
 * Throughout the level, you can hear the sound of the Rhino roaring. The Rhino can be seen in the background in the model viewer in the top right. Why the Rhino is presumably on the surface is unknown, but it could simply be something the developers added in to give the place more life.