4 Heavily trained female's tasked with covering up the Black Mesa Incident (Resonance Cascade) which cause Extra terrestral life forms to Invade earth all of them are dressed in Latex suits with the capabilities of turning translucent all of them have Heel springs which allow them to jump way up in the air they are equipped with grenades and suppressed Glock 17s they are also very agile and nimble but all you need to know is that their mission is to silence you by eliminating you