Employers (Half-Life)

The Employers are an enigmatic extradimensional group who were responsible for manipulating history to meet an unknown agenda, most notably the Black Mesa incident and Combine domination of Earth.

History
Little is known about the Employers, other than what little was implied by their representative, The G-Man (the term 'employers' was used by the G-Man in reference to them, and even this term was used after a moment of hesitation, implying the name was simply something he improvised while in conversation with Gordon Freeman). The earliest known example of the Employers' meddling is the Black Mesa incident, when the G-Man provided the anomalous materials researchers there with a crystal specimen from the border-world Xen, and even recommended analysing it with the Anti-mass Spectrometer at a higher-than-normal capacity, directly causing the resonance cascade that drew the Combine to Earth. During this incident, the G-Man monitored theoretical physicist, Gordon Freeman, as he fought through hordes of aliens teleported from Xen, as well as the HECU marines sent to cover-up the incident. When Gordon travelled to Xen and killed the Nihilanth leading the invasion, the G-Man saved him from the Nihilanth's destructive death throes, stating that the Employers had authorised him to offer Gordon either 'a job' befitting his capabilities, or certain death on Xen, in response to his recommendation on the scientist. Gordon accepted the G-Man's offer and became trapped in suspended animation. During the Black Mesa incident, the G-Man also monitored a HECU marine, corporal Adrian Shephard. Fighting through Xen aliens and an incursion of Race X, Shepard disarmed a nuclear warhead a military black-ops unit intended to use to destroy Black Mesa. However, the G-Man reactivated the warhead and extracted Shepard before it detonated. Despite his vouching for Shepard's skill and likely discretion for his knowledge of what happened at Black Mesa, the Employers deemed him a liability, and so had him detained outside of time and space for the foreseeable future.

Twenty years after the Black Mesa incident, the Human race had been fully subjugated by the Combine. By this point, the G-Man, likely on orders from the Employers, released Gordon Freeman from stasis and placed him in City 17, monitoring his journey as he led the resistance in a full-scale uprising against the Combine. When Gordon and Alyx Vance critically damaged the dark energy reactor of the Combine Citadel, the G-Man attempted to extract Gordon once again, removing him from the fight against the Combine and leaving Alyx to her fate in the Citadel. However, both Gordon and Alyx were rescued by the Vortigaunts, removing the former from the Employers' influence. However, after Alyx was mortally wounded by a Combine Hunter, the Vortigaunts became occupied in healing her, allowing the G-Man to speak with Gordon once more. However, rather than attempt to reassert his influence over him, the G-Man had Alyx deliver a message to her father, Dr. Eli Vance. Upon learning about the lost Aperture ship, the Borealis, Alyx, seemingly in a brief trance, passed on the message to Eli; "Prepare for unforeseen consequences." In conversation with Gordon, Eli reveals an apparent connection between himself and the G-Man, revealing the extent of the Employers' involvement in the Black Mesa incident. However, the nature of this connection and his knowledge would remain unknown, as Eli is killed by a Combine Advisor shortly afterwards.

In an alternate timeline, the Combine were somehow succesful in containing the G-Man, trapping him within an extradimensional prison facility known as the Vault five years before Gordon Freeman's arrival. He was freed by a younger Alyx Vance, who initially mistook him for Gordon. During their conversation, the G-Man explains that through him, the Employers 'nudge' events and individuals to alter history itself to suit their intentions. When Alyx asks the G-Man if the Employers could remove the Combine from Earth, he declines, stating that such a request was too great and contradicted the Employers' interests. This explanation creates implications of the Employers' potential limitations, the G-Man's capabilities and restrictions, and their complex relation with the Combine, due to enabling them to conquer Earth as well as empowering the resistance to oppose them. As compensation for his release, the G-Man shows Alyx a vision of Eli's death in five years and offers her a chance to save his life. Accepting the offer, Alyx is bought forward in time and kills the Advisor before it could kill her father. However, the G-Man then abducts her, using her as a replacement for Gordon after he 'disappointed' the Employers with his insubordination.