Sector C Test Labs is one of the seven main of the Black Mesa Research Facility. This Sector is notable primarily for housing the Anomalous Materials Laboratories, Gordon Freeman's workplace. Anomalous Materials also contains the Anti-Mass Spectrometer, the initial source of the Black Mesa Incident and what can be called the true starting point of the Half-Life series. The Anti-Mass Spectrometer runs across the three main levels of Sector C, from deep underground to the surface.