Separation (Metro Last Light Level)

"We pulled off the impossible...Now I have to inform the Order that the Dark One is missing. Which means to acknowledge that I've failed my mission, but now, when he's down in the Metro I won't be able to find him alone. I have to get to Polis, the Order's HQ. Pavel will show me the way."

- Level description

Separation is the sixth level of Metro: Last Light.

Overview
Pavel is captured by Reich soldiers in this level and Artyom must either sneak or fight his way through a Reich outpost in order to save him. The stealth approach isn't particularly hard as long as the player stick to the shadows, shoot or otherwise extinguish sources of light, looks for alternate routes past well lit areas, and eliminate the Nazis walking off into the shadows.

Diary Entries
5. After the door opens and two guards come out to look for you there is a little guard room. The note is in the center of the room, on the computer panels.

6. During the same mission you will open a door and there will be a man who surrenders, the note is on the table to the left just inside the room.

Moral Points
Gain: Lose:
 * Complete the level without killing any humans, or simply don't kill the man reading on his bed after he surrenders.
 * After exiting the first area of Nazis, kill the man reading on his bed after he surrenders.

Trivia

 * A Reich soldier with a pair of headphones can be found sitting on his chair jamming out to "The Market", a track from the soundtrack for Metro 2033. Since his eyes are closed, he will never see you unless unsuppressed gunshots are fired (by anyone), or if you come into contact with him.
 * In the main area of the outpost, on the elevated tracks, is an armoured train with a Panzer turret on its roof.
 * Early in the mission where Pavel gets captured by Reich sentries, a soldier exclaims "Real fucking ninja..." This may be derived from the phrase "That was pretty fucking ninja" which was uttered in the HBO series Generation Kill.
 * The surrendering Nazi soldier is seen reading the book called The Evolution of Species by Charles Darwin.
 * If you stay stealthy, don't move to hear a conversation between two Reich soldiers talking about how their friend, Mikhel going to a brothel in Belorusskaya, where the man met a girl with a "real tail". They also mentioned how their Hauptsturmführer said to Mikhel that he will hang next to her tomorrow or punish her. They also mentioned how Mikhel decided to beat her up with a broom stick.
 * The Gatling was featured in the E3 gameplay demos showcasing the level. However, in the final version, it was cut - most likely due the level being too early.
 * Also in E3 gameplay demos Khan will assist Artyom to escape the Fourth Reich, while in the final game Artyom must rescue Pavel from hanging.
 * Another thing left over from the game's beta is when the player is at the airlock, the opposite room has a circular shape that's been roughly patched over. This was the original entrance in the E3 demo, where the player would have just come from the swamps but the moss outlines still stays the same in the Redux version.
 * A screenshot from the E3 demo can be seen on the loading screen showing the eagle symbols which was the original insignia found on the backs of Reich soldiers.