Find the Hiding of Strelok's group

Your hunt for Strelok led you into Agroprom Underground, where you are trying to find his hideout.
== Walkthrough ==
Agroprom Underground will likely be your first exposure to plagued rats, so you might want to read about Plague and how to avoid or treat it before you die.
=== Teleport puzzle ===
The Strelok's hideout is located in a ventilation shaft somewhere in the tunnels, but the entrance is blocked by a teleport. To get past it, you have to walk through the series of teleport throughout the location. The teleports are brightly visible and their hum can be heard from a distance, so you won't have trouble finding them.
The first teleport is a decoy which is located at the top of the main staircase. It disappears as you touch it.
The second teleport is in the bloodsucker tunnel. Beware of a bloodsucker that spawns as you enter the tunnel.
The third teleport is at the other end of the electra tunnel. Run through the tunnel by properly timing it, without leaving the tunnel (easier said than done).
=== Hideout ===
After stepping into the third teleport, you'll be placed onto the ladder of the ventilation shaft. Climb upwards and reach the Strelok's hideout. Grab Strelok's flash drive from a niche in the wall. Upon picking it up, a bloodsucker will spawn in the bloodsucker tunnel.
Before leaving, make sure to look behind the large pipe near the exit of the hideout, and pick up a PDA that disables the entrance teleport. If you don't do that, you'll lose the access to the hideout, because the teleport puzzle is single-use but the entrance teleport will stay forever. The only way to disable the teleport without it is to buy the code from Adrenaline for 20,000RU later.
There's also Strelok's suit which is a great armor early on due to the strong HP regeneration, and it's also required in Body armor for Fiend.
=== Finishing the quest ===
To finish this quest, proceed to the the controller tunnel in the Underground. You don't actually have to exit, just trigger the restrictor at the end of the tunnel. Then you can either proceed to the military base, or return back to the factory complex if you are raiding the underground during the night (to avoid the angry Sherstyuk).
After triggering the restrictor and finishing the quest, a zombie spawns in the controller tunnel, and a controller spawns in the bandit chamber, blocking your way back into the factory complex. It won't despawn, so you'd better kill it to avoid difficulties later.
== Notes ==
* If you miss your chance and fail to pick the PDA up while inside the hideout, the entrance will be blocked. However, you could pay Adrenaline 20,000RU to have him remove the teleport.
* After this quest, Mole moves to the campfire behind the bandit base in Dark Valley.
* This quest can be conveniently combined with Old documents: part 2 from Akim, as the stash you look for is inside the electra tunnel.
== Bugs ==
* Leaving the Electra passage without making it into the teleport has been reported to break the quest.
* Don't forget to finish this quest before descending into X-16, otherwise you'll softlock your game. This is an old bug from Shadow of Chernobyl.