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We're trying to collect a new type of samples at the moment. They don't have any anomalous effect on their own, but experiments we conduct with them produce incredible results! The stalkers who found the psy-field believe that it contains a mutant lair. I don't really believe them... I mean, no mutant other than a controller can survive in an intermittent psy-field! Don't worry, our boys will deal with the mutants. We need you simply because regular contact with psy-fields has reduced our stalkers' resistance to their effects.


Intermittent psy-emissions is a side mission available in S.T.A.L.K.E.R.: Call of Pripyat


It is the first mission given by the Ecologists in the Mobile Lab, but the player will only get it after he has a helmet with sufficient psy-protection. The player needs to wear one of the following armors to get the mission:

After accepting the mission from Professor Hermann, the player must then speak with Topol outside the lab. Topol and his team will cover the player as he moves in through the North-western tunnel to discover the origin of the psi-emissions that the scientists have observed there.

The player enters the tunnel with the team. After taking care of a few Zombified stalkers that are in the tunnel, the team covers the gate of the chamber that the player must move in to and explore. The psy-emmissions inside the chamber will start giving the player damage, so the use of Psy-block might be a good idea.

The chamber consists of three rooms, full of Electro anomalies, however these are rather easy to avoid, especially with the use of bolts. The first room is dominated by a moving Electro anomaly. This moves in a predictable, circular fashion; one can follow it halfway into the room and then move diagonally, past the container towards the entrance to the next room. There is a TRs 301 and 5.56 ammunition stuck beneath a container in this room. The second room contains various medical and ammo supplies. The third room contains vodka, ammo, an AKM-74/2U and the Altered Insulator, the unique artifact that had been causing the emissions.

While everything should be going smooth up to this point, after picking up the artifact and exiting the door the player is warned by a convulting Topol  that a Controller has appeared. There is little time to react; soon, the Controller will order Topol and his men to attack the player with their guns and grenades. If left unattended, the controller will force Topol's group to attack the player, meaning it is advised to take down the controller quickly to avoid such. It is best to load a shotgun, sprint towards the mutant while staying out of his sight (so it cannot use its psychic attack) and quickly take it down. Even simpler: one shot from the RPG-7u found in Volkhov AA Complex.

If Topol's team dies in this mission, the reward shrinks by 1000 RU for every slain stalker, from a maximum of 6000. It also makes it more difficult to earn the Researcher achievement by lowering the reputation if the player had to kill any of them. The reward for the second Ecologist mission also shrinks drastically.

After the player kills the Controller, the Ecologists will hold their heads a little longer, trying to get their bearings, and then exit the tunnel quickly. Once outside, Topol thanks the player for saving his life and gives them the coordinates of a stash in the Kopachy village containing a Veles detector and medical supplies. Back in the bunker, the player hands the artifact to Hermann and receives a maximum of 6000 RU in reward. Also, trading with Hermann now becomes possible. The Altered Insulator is placed on display in a container in Hermann's laboratory.


The player will receive a stash location from Topol if he survives, and 6000RU from Hermann if all stalkers survived.

It will be possible to trade with Hermann after completing the mission. As well, controllers will spawn at the tunnel and in the open in Yanov once the mission is completed.


  • On their way out after accepting the mission from Hermann, the player can ask Novikov for advice regarding the mission. However his answer is of no real use, only warning that prolonged exposure to psy-emissions can zombify a stalker.