Socialist Tension is a Single player Half-Life 2 mod, where you are in the role of a Contract killer, who was sent to City 17 for his next assignment. His client, one of the citizens of City 17 wants you to assassinate Dr. Breen and put an end to his domination. But he doesn't know that the "death" of Dr. Breen will lead to tragic consequences and thus your only hope is to get out of City 17 as soon as fast. Good luck. The mod only adds some new maps, there aren't any weapon/NPC changes.