Barchuk was a mercenary appearing only in S.T.A.L.K.E.R.: Call of Pripyat.
Call of PripyatEdit
When searching for Lab X8 in one of the buildings in Pripyat, the player will encounter Barchuk's corpse just outside the elevator shaft. His PDA indicates that the backup generator on the sixth floor is still operational and can be used to give power to the elevator which leads to the underground lab. However, he was ordered by Serbin not to turn it on, instead guarding the entrance to the facility until Jackal arrives.
The presence of zombified stalkers and Monolith troops in the building indicate that he was easily dispatched by hostiles even before, during, or shortly after Serbin's transaction with Jackal.