Pathfinder: Shadow of Chernobyl
He is known throughout the Zone and the black market for being the only reliable connection between the Zone from the outside world. He achieves this with the help of his contacts within the army inside the Cordon who tolerate his presence as he can provide luxuries that would otherwise be difficult to come by. There is a common saying amongst Pathfinders that if Sidorovich can't complete your shopping list, no one in the Zone can.
Sidorovich was one of the first people to enter the Zone, arriving at the outskirts in 1364. He conducts all of his business out of a manor house located by Putrivka and just south of the Cordon. He handles nearly all of his business from within the manor, saying that he's not the fighting type and won't survive long outside.