Find out what happened to the Alexandrych's squad

Alexandrych told you that his guys disappeared six hours ago somewhere between the [ Tuzla tunnel] and [ ruined village]. He asked you to find them and the boxes they were carrying, and advises to check in the [ hidden cave] first, where this group was last contacted with.
== Walkthrough ==
This mission involves a huge mutant massacre. Come with an UBGL and/or a lot of hand grenades, and make sure you can haul 36kg of quest items. The mutants from this mission will not despawn, so you'll have to fight. It will be significantly easier to complete if you wipe the controllers from the boat station out before accepting it.
Refer to the following video which might be clearer at explaining what's going on than the article.
=== Initial waves ===
After speaking to Alexandrych, three waves of mutants will spawn; to the left, right, or behind the player, but never under the direction of sight.
You might want to read on the mechanics of large mutant battles to understand how they work, because it can be confusing.
The waves are always centered on you, regardless of where you go, and spawn on the times as long as you're out in the open. If you hide somewhere, they will cease and start spawning again once you exit your hideout.
* immediately - tushkanos and zombies.
* 2-3min later - large boar, fleshes, and a biomass.
* 1.5-2 min later - zombie gopniks and a pseudogiant.
The best way to deal with them is to ignore the first wave (Alexandrych with deal with it easily), sprint towards the water tower in the ruined village, and climb it. Wait up to 5 min for all waves to spawn. Note the place where the second wave (with fleshes and a huge boar) spawned - there will be a biomass there. It spawns far enough to not cause you any problems on the tower, but needs to be dealt with later. After the third wave with gopniks, make some noise and attract them under the tower. A couple grenades will make short work of most of the mutants.
More mutants will spawn near the hole in the fence (parasites and a plagued zombie), and on the way to the boat station (a group of zombies).
=== Alexandrych's squad ===
Head out to the [ hole in the fence] and check the bridge area. Walking over the circled portion of your PDA map will spawn the wounded stalker and his friend's body, along with the controller responsible for the disaster in the fishing village. 
Under the bridge, you will find one of the stalkers from Alexandrych's squad; he's dead and has the box (12kg) on his body. Inside the [ hidden cave] you will find Petrovich, another stalker. He's badly wounded and will refuse the medkit you offer, but will tell what happened to them: a controller from the boat station zombified one of them, and made him shoot others. After that, he will give you his box, and die. 
Exiting the cave will trigger another large mutant spawn, similar to the initial waves. Deal with it in a similar manner - climb the water tower and wait.
The third box should be on the body of last Alexandrych's stalker, located inside the cellar right next to the water tower. You must walk through the center of the circled portion on your minimap to spawn the body. 
Descend into the heavily irradiated cellar, pick up the final 12kg box off of the body, and leave immediately to avoid being bodyblocked by any mutants. This will also trigger another snork spawn, and another set of waves. Keep in mind that winged snorks can sometimes jump onto the water tower.
After finding all three boxes and killing all mutants, report to Alexandrych. He will give you a monetary reward and directions to a tricky stash with a good weapon.
=== Reward at the Swamps ===
Your reward is MP-153S "Murka", a great shotgun. However, you will have to work for it. Potential spawning locations are marked on your map. You'll have to find the stash in one of them, always in the center of the marker circle. If there's none but you came close enough to the place where it should have been, you'll hear the laugh, fight a random mutant (yes, even including plagued zombies) and have to seek in another marked place.
There are 20 potential spawn places for the stash. Although the video shouldn't be required as the places are easy, all of them are shown below, with timestamps in the description:
=== Reward on the Jupiter ===
Extra reward for this quest will be waiting for you in Jupiter, the location you unlock much later during the Black Doctor's exoskeleton storyline. The stash is on one of the containers in the [ Warehouse]; it's marked on your PDA map so it's hard to miss.
After taking the stash, four mutant waves will spawn:
* librarian and two mosquito zombies
* two leaping pseudogiants and a bunch of zombies, including an exploding one
* three pseudogiants and a half dozen snorks
* giant mutated bear, two pseudogiants, two inferno bloodsuckers, half a dozen chimeras.
Each wave comes in several minutes after another. These waves are centered around you, they aren't spawning in a fixed place on the map.
== Notes ==
* If you accepted Rabbitfoots but haven't completed it yet, a bunch of zombified stalkers will spawn after approaching the hole in the fence, adding to the confusion. Refer to Rabbitfoots for details. It's better not to stack both of those quests.
* The water tower area contains an artifact decay restrictor. Refer to Artifact decay to be aware of its size, and not to cross its border too many times accidentally.
* Make sure you try to keep track of the two biomasses that spawn on this quest, as running near them with low psi resistance can kill you very quickly.
** Make usage of third-person camera mode to get a better idea of your surroundings if you cannot find them.
* Waves can safely be pulled to Alexandrych or Dan as both are invulnerable.
* Gopnik zombies have an exceptionally high droprate for zombie hands, and this quest can easily yield 20 or more. This is especially useful if you still need 40 zombie hands for Akim.
== Bugs ==
* This quest seems severely bugged in general, and Petrovich can be missing from the cave sometimes. Reload if that happens.
* The medkit dialogue for Petrovich still appears even if you do not have a medkit.