The Heist is the final mission in the game. In the mission you cannot teleport back to your base. You also cannot build tools and craft any items. Resources in your inventory waste slot that are better used for ammunition, plates for armor, medikits and so on.

You can start the Heist at any point in the game. Even in the first day, it you want. You will certainly die soon...

You must prepare for the Heist. You should have all companions in the team and you should have collected all tools (Heist components). You must have finished the investigation boards in Igor's room to convince your companions to go with you to the Heist.

You can give a strategic role to each companion. You can have:

• One or two Infiltrators (requires the uniforms)
  
• One technician (you can choose Tarakan or Olga here. I lost Olga several times, this never happend with Tarakan)
  
• One Sniper
  
• One Spy

The following tools can be found during normal story missions before:

• Password (from quest Kidnapping Kozlov)
  
• 2 Uniforms (from quests Checkpoint assault and A few things from an old hideout)
  
• Charges (from quest Hardware for real man)
  
• Power plant plans (from quest Chain reaction)

The game has 3 endings. You can reach every ending, no matter what you did during normal missions. There is no hidden karma counter or so like in Metro. All you have to do is to finish the Heist mission. Your companions might die during the Heist, but you can finish the mission anyway. However, there is a way that all companions will survive!

Semonov: If you did not kill Semonov before, he will release shadows during the Heist. One of your Infiltrators dies and Igor gets involved in a fight against Shadows.

Kozlov: If you freed Kozlov's nephew and did not help Kostya to poison Olga's village and told Kozlov where to find Glyeb, then Glyeb is thankful and so Kozlov helps you by pulling off the guard before the lab.

Olivier: If Olivier's relationship status to Igor is good or great, then nothing happing. If the relationship status is neutral or bad and Olivier is in your team, then Olivier will kill Igor during the Heist. This happens if Olivier is part of the Heist team or if you left him behind at the refuge. If the relationship status is terrible - that's curiously ok!
If you kick Olivier out of you team before the Heist, then he will not kill Igor. (You only need one infiltrator so that might be ok. But Olivier will not get mentioned in the post game dialog, where the future of all persons is told. If you want to know what happens with all companions, then make sure that Olivier has at least a good relation.)

Companions that left you because of a terrible relationship status:

• Olga will kill an Infiltrator at the first security door.
  
• Mikhail will kill an Infiltratot at the Golden corridor.
  
• Sashko: I did not encounter any bad events.
  
• Olivier: Nothing bad happens. I think this is a bug :)
  
• Tarakan: I have no information yet, have to replay the game to make him left the team.

I show all decisions together with the available options and the outcome in some diagrams.
The spot where Igor has to choose is on the left side. Arrows indicate the options. (Some options might be missing. They have some requirements (Roles of your companions and/or tools). For instance: you only have one sniper - if your Sniper dies or his position is revealed, he is not available in the future anymore. You also have only one Charges to blast a door look - which you (obviously) can use only once.)

If the color of the result is red, then something bad happens.
If the color is orange, then the immediatly result is ok, but you might run into problems later.
If the color is green: perfect!

If an Infiltrator is going to die and if there is no Infiltrator left at Igors side then Igor dies instead of an Infiltrator.

After all previous decisions you have to fight the Black Stalker. You can try to run, fight, spend a lot of ammunition, use lots of healing stuff.
But if you have trouble in the fight, you might change difficulties before the fight or use a special tactics. (In my eyes this way is far too easy and I hope this will be changed.)

The fight has 3 Phases.

Phase 1: Black Stalker #1 appears upon a platform at a wall. (I think this is the only position where #1 can appear.) There will be a second Black Stalker appearing on the floor somewhere near Igor. They both don't move, they will shoot several times at Igor and use a portal to vanish for a short time.

Phase 2: As soon as Black Stalker #1 vanishes, Black Stalker #3 appears near Igor. He does not shot, but he generates some sort of circular area damage. The area is marked red, and after a few seconds Igor takes damage if he is in that area. Black Stalker #3 disappears after the blow.

Phase 3: The fight remains the same as in Phase 2. At the beginning some extra Chernohosts are spawn near Igor at the floor. From time to time another Chernohosts may spawn. If have not figured out, what causes their spawning. It seems that the Chernohosts spawn, if Igor tries to just run and hide without fighting. Good for Igor: if a Chernohost is withing the damage area of Black Stalker #2, he will die.

Special tactics: This even works with insane difficulties. All you need is enough ammunition. (A railgun with a regerating magazine is sufficient.) You don't need armor, plates or any healing stuff. If you play correctly Igor won't get hurt. (You might start the Heist with 1 hitpoint only :) )

After the conversation with Black Stalker(s) at the beginning, he (and his two clones) will disappear. Turn right, and walk to the follwing electrical control box:


You can climb it easily. If you are on the electric control box, the Chernohosts cannot reach you from the floor. If you stand behind the upper cooling fins? Black Stalker #1 also cannot hit you with his gun. All you have to do now is: wait for your raingun to have 3-5 ammunition. Take some steps forward (but stay on the box). If Black Stalker #1 appears at his platform, step back behind the fins and shoot at him. When he vanishes, wait for the portal to open for Black Stalker #3 and step back and jump from the box. Wait 2-3 meters behind the box and behind the red circle. Climb the box again. (If you too fast here, Black Stalker #3 may appear behind you. In this case, just run out of the red circle.)
(In insane the most problem are Chernohost that appear unexpected in the wrong moment. They make a spawning sound. If this happens, it might be better to stay at the box and take the damage from Black Stalker #3.)

The requirements for your companions to join you in the Heist mission are:

• Sashko: will always join you :)
  
• Tarakan: finish investigation board "Web of Lies"
  
• Olivier: finish investigation board "Black Stalker"
  
• Olga: finish investigation board "Woman in red Dress"
  
• Mikhail: collect 4 tools.

Minimum number of tools:
With no uniform you cannot take an infiltrator with you. So you only can recruit a sniper, a spy and a technician. You need Olga and Tarakan for technician and spy. To have Olga in the team, you have to finish the 3rd investigation board. To get all the clues for that board you have to do the mission "Chain reaction".

Tools: only Power Plant Plans
Sniper: Sashko
Spy: Tarakan
Technician: Olga

Minimum number of companions:
With all tools, you only need 2 companions.

Tools: all tools (power plant plans are not used, but you will have them anyway.)
Infiltrator: Sashko and Olivier

All companions can have at least neutral reputation:
I often read in the forum or in let's plays that it is not possible to satisfy all companions, and that at least one companion has a bad reputation.
That's not true. You can have Olivier a good and all other companions a neutral reputation.