Lana

The setting takes place in the Black Research Facility from the Half-Life games during The Black Mesa Incident.

The Black Mesa facility was apparently built over several decommissioned ICBM launching and testing silo complexes probably constructed during the 1950s, which was converted into a vast civilian institute for the research of almost every conceivable scientific discipline. Several Half-Life texture files' names contain the word "fifties", suggesting the facility is as old as from the 1950s. Some areas are also described by characters such as Rosenberg as "old" or "abandoned"; several areas of the complex are badly run-down despite the obvious fact that they are still in use. However the surface areas of Black Mesa feature more modern construction. Black Mesa undertakes its various scientific researches in the facility, which is a very high-security complex, as each employee is required to undergo a series of rigorous security checks to access most areas. Security guards, carrying firearms and trained for emergencies, are present in all of the facility. The complex is also equipped with retinal scanners and alarms, as well as heavy blast doors that may shut down in case of fire, explosion or other event. Black Mesa can be completely sealed from the outside. Tram interior One of Black Mesa's modern electric trams riding along the Black Mesa Transit System.

The facility is self-sufficient, housing its own: ventilation, cold and hot water, central heating, sanitation, drainage, and power generation systems including a Hydro-Electric Dam and multiple types of electrical generators and reactors, some using nuclear technology. Chemical processing plants are also seen and as the facility is located within the desert water treatment plants are required to recycle waste water. The complex is dominated by a number of underground laboratories, test areas (including an Anti-Mass Spectrometer), and administration offices, most of which contain very high-tech equipment, and even a rocket launch site. The complex also features multi-story car parks (where only Black Mesa SUVs can be found), arsenals of nuclear and conventional weapons, and a local electric rail materials transport network, Sector E Materials Transport. Black Mesa is also apparently kept supplied by a conventional freight rail linked to the outside, managed in the Freight Yard. Vaguely repaired An example of the state of disrepair of some parts of the facility, here in a roughly repaired toxic waste storage unit.

As employees are required to live in the complex itself, Black Mesa contains many personnel facilities, including laundromats, recreation and sports areas such as lounges, at least one basketball court, at least one swimming pool, a library, fast food outlets, food courts, cafeterias, and numerous vending machines. The facility is well-populated by rest areas and dormitories for the employees of the facility. As Eli Vance reveals in Half-Life 2 that his wife and daughter lived in Black Mesa with him, it can be inferred that employees' families reside in the dormitory complexes as well. All main Sectors are linked together by the Black Mesa Transit System, the monorail network going through the whole facility. Black Mesa is equipped with a public address system, the Black Mesa Announcement System, relaying audible messages and announcements across the facility with a male voice. It is also used in the Black Mesa Transit System to give general information about the facility and mention each stop, with a female voice. The complex also has its own newspaper, The Mesa Times, which is sold within the Black Mesa Research Facility to inform the personnel about events within and outside of the facility. Despite being located in the middle of a desert, the underground and indoor sectors of Black Mesa are "maintained at a pleasant 68° Fahrenheit (20° Celsius) at all times", enabled by Black Mesa's sprawling network of ventilation ducts. In the underground laboratories, administration offices and dormitories, the main sections are always indicated in important intersections areas, and follow color codes consisting of lines running along the corridors to the related location. Several colors can be seen running along corridors, disappearing each time a related location is reached. This is seen for instance in Sector C and the Level 3 Dormitories. Overall, Black Mesa is almost as large as a city and is completely self-sustainable in all fields. In the event of an emergency, the "military" and "trained assassins", referred to as "a dangerous and very efficient clean-up crew" are to enter the facility. This suggests that Black Mesa has experienced problems with escaped specimens in the past and that a possible intervention from the HECU and the Black Ops is a known fact among the personnel, although some employees consider it a rumor Possibly to deal with potential escaped specimens, or perhaps being a leftover from the facility's days as a military missile complex, Black Mesa contains many automated ceiling turrets, which, when activated, will emerge from armored cupolas and fire upon any moving object in their line of sight.

Sector A of the facility is the Training Facility Sector B of the facility is the Coolant Reserve Sector C of the facility is the Test Labs Sector D of the facility is the Administration Sector E of the facility is the Biodome Complex Sector F of the facility is the Lambda Complex Sector G of the facility is the Hydro Electric

Occurring sometime in 200-, the Black Mesa Incident is caused directly by a failed experiment in Sector C, triggering a Resonance Cascade. This leads to the invasion of the facility by Xen creatures and Headcrabs to appear around the facility infecting the other scientists.

Headcrabs are alien parasitoids, roughly the size of a pumpkin. They are covered in smooth skin that varies in color between subspecies, and walk on four legs comparable to those of a spider. The shape and length of these legs relative to the mass of the body varies between Headcrab subspecies. Headcrabs are capable of leaping up to 3 meters (10 feet) in any direction, but will only perform this leap as an attack, and require a direct line of visual contact to their target before they will do so. If they miss their target when leaping, Headcrabs are placed in a disadvantageous position, as it must turn completely around at a very slow speed before attempting another.

Their underbelly is almost entirely covered by a large, jawless mouth, with a hidden 'beak' used for feeding and for latching onto the skulls of victims. Headcrabs are a parasitic species. Upon sighting a humanoid host, a Headcrab will leap for the victim's face and affix themselves to the head, where upon they will use their beak to break into the victim's skull, and dig their legs into the victim's upper torso. The Headcrab then proceeds to take over their host's body through an unknown biological process, however it is assumed that it will penetrate and seize control of the brain stem and thus the signals controlling the motor functions of the host body. The host will then undergo physical changes, presumably induced through chemical means; although the mutations vary between Headcrab subspecies, common changes include the deterioration of flesh (which also gives an illusion of longer fingers), reduction or removal of skin and muscle tissue across much of the body, and the exposure of the organs inside the abdominal cavity. Headcrabs keep their host alive throughout the entire process, unable to remove the Headcrab. It can take anywhere from several seconds to several minutes for a Headcrab to convert their hosts into Zombies.

The host appears to stay in some state of consciousness once the Headcrab has taken control. Standard Zombies retain a certain ability to talk, always heard as violent cries for help. "Zombines" seem to be able to speak with their vocoders. Each Headcrab subspecies affects their host in their own unique way, producing a Zombie extremely distinct from the other types, in both appearance and behavior.