Escort Kruglov to Yantar

Kruglov is asking you to protect him while he makes his way back to Yantar.
== Walkthrough ==
If you're attempting to save Kruglov's team, make sure you wiped the entire location before taking this quest. (See Meet Kruglov)
After the dialogue, 6 more mercs will spawn by the crashed helicopter. If you're trying to save Kruglov's team, kill them before they kill any of the scientists, and double-check that all 4 of them are still alive. A RPG-7 is recommended, as it can wipe the mercenaries in a single shot.
Meanwhile, Kruglov will start moving towards Yantar. As you pass the construction site, more mercs will spawn around and in the Burner tunnel, so run there ahead of Kruglov and kill them before he has a chance to die.
At the entrance to the [ Burner tunnel], Kruglov will stop and tell you to go first. Do this by sprinting through Vortexes in the tunnel. After that they will shut down while Kruglov and his team travel through the tunnel; if you don't do this, they will be torn apart by them.
Listen to the mercenary named Ashen threaten you over radio for the death of his men and letting Kruglov slip away with his research. Wait for Kruglov to cross the tunnel and stop.
If you're saving the scientists, get back and escort them, making sure that all 4 passed Kruglov on their way to Yantar. After they did this, talk to Kruglov and receive the flash drive, your achievement, and the Living Heart. His scientists become unimportant after this.
After talking to Kruglov, wait for him to start running towards Yantar and disappear from the location. The transition to Yantar will open after Kruglov enters it.
== Notes ==
* As Kruglov advises, give his flash drive to Barkeep after you brought him the documents in Find documents in the laboratory X-16; he will pay you 10000RU and the transition from Bar to Army Warehouses.
* If you're saving Kruglov's scientists, you can talk to any of them to make him pause and wait for the others.
== Bugs ==
* Saving and loading the game can break Kruglov's script, preventing him from walking to Yantar and opening the transition. After he crosses the burner tunnel, try to avoid loading the game.