Alyx Vance's History
Alyx Vance is the deuteragonist of Half-Life 2 and its Episodes and the titular protagonist of Half-Life: Alyx. A young woman in her mid-twenties, she is a prominent figure in the Resistance campaign against the rule of the Combine.
Childhood
Alyx was born in 1996. As a young child, Alyx lived in the dormitories within the confines of the Black Mesa Research Facility along with her father Eli and her mother Azian, while Eli was working at the Sector C Test Labs. When the Black Mesa Incident occurred, Eli managed to escape along with Alyx and a family picture, while Azian was killed in the incident. During the course of the incident, the G-Man was instrumental in rescuing Alyx, despite the objections of unnamed naysayers. Alyx was apparently too young to remember this, and although Eli witnessed it, he never shared the story with her.
Alyx was raised by Eli in the world controlled by the Combine, likely at Black Mesa East much of the time. During this time, Alyx was also on good terms with Isaac Kleiner, referring to him as "Uncle Kleiner" in an affectionate portrait she once offered him. During Alyx's childhood, Eli used scrap metal to create Dog, a sentient robot designed to protect her, making him physically powerful, intelligent and with an in-built sixth sense so that he could always know Alyx's whereabouts. Although the initial model was a mere meter high, Alyx added new parts to Dog over time, making him a towering 2.5 meters high at the time of Half-Life 2.
As Alyx reached adulthood, she began working with the Resistance, as one of the core members of the City 17 branch, most notably assisting Kleiner and Barney Calhoun in helping citizens escape the city to Black Mesa East through the old Canals, as well as helping Kleiner, her father and Judith Mossman establish a teleport connection between Black Mesa East and Kleiner's Lab. She is working with this at the time of Half-Life 2.
Later Years
Alyx is arguably the most important character in Half-Life 2, as she helps Gordon Freeman more frequently and directly than any other character. Her first appearance is in the first chapter of the game, Point Insertion, in a scene where Gordon has been intercepted by Civil Protection units while he is still an unarmed civilian, due to a miscount detection. By the time, Alyx rushes in the room and takes down the CPs by herself (although this is not explicitly shown on-screen). Subsequently, she escorts Gordon to Kleiner's Lab, there they meet up with Barney and Kleiner. After Gordon puts on his HEV suit, they enter the teleport room to be teleported to Eli Vance's lab in Black Mesa East. However, the two unintentionally part ways after Kleiner's teleportation device malfunctions, forcing Gordon to continue through City 17 on his own.
When Gordon eventually arrives in Black Mesa East, he is welcomed by Alyx and her father. Later on, she gives Gordon the Gravity Gun and demonstrates its use. Alyx is also shown having a heated argument with Dr. Judith Mossman, a hostility that appears justified as Mossman is revealed a traitor in the chapter Entanglement, where Gordon helps Alyx search Nova Prospekt for her captured father.
In the chapter Anticitizen One, she fights alongside Gordon through a section of City 17 during the armed uprising but they are again separated when Alyx is kidnapped by Overwatch Soldiers while scouting an escape route from a rooftop vantage point. They are reunited later in the chapter Dark Energy, when Gordon reaches Breen's office in the Citadel. There she provides indirect assistance to Gordon during the final confrontation with Dr. Breen in the Citadel's dark fusion reactor. Alyx also seems to have made peace with Dr. Mossman after seeing her turn on Dr. Breen and release Gordon Freeman, Eli and Alyx herself from their imprisonment.
In the ending scene of Half-Life 2, Alyx is with Gordon at the time of the Dark Energy explosion. While the G-Man saves Gordon from the enormous blast, Alyx is apparently left behind, frozen in time with one arm shielding her eyes.
Alyx manages to survive, being rescued by Vortigaunts, who also free Gordon from the influence of his "employer", the G-Man; after being teleported away at the foot of the Citadel and briefly revisiting it to postpone the destruction of the Citadel Core, Alyx and Gordon stick together for most of Episode One, finally getting to the exit from City 17 and jumping on the last Resistance train wagon heading out of the City just as the Citadel explodes.
Alyx appears in Episode Two throughout the game, and is almost always with Gordon. She once again rescues Gordon at the beginning of the game by using the Gravity Gun to free him from the remains of their crashed train, which fell off a bridge that was destroyed because of the Citadel explosion at the end of Episode One.
After making a first communication with White Forest, a large Resistance base, she is severely injured by a Hunter, but Gordon and a Vortigaunt manage to steal Antlion extract and use it to save her. During the process of reviving her, the G-Man reappears and informs Gordon that the reason Alyx remained alive during the events of Half-Life 2 and its expansions is because he "plucked" her from Black Mesa before the Resonance Cascade destroyed the facility, ignoring the orders from his superiors - that she was a mere child and of no practical use. He tells Gordon to escort her to White Forest safely, telling Alyx to relay the words "prepare for unforeseen consequences" to her father. She then accompanies Gordon on their journey to get to White Forest. Throughout the journey, she helps Gordon at many points, by providing sniping support for him using a mounted Combine sniper rifle as he makes his way through a Zombie-infested industrial complex to get to the Muscle Car or by using her gun on enemies while he is driving.
At the end of the game, her father Eli is killed by an Advisor before she and Gordon get into a chopper to go looking for Dr. Mossman. While she and Gordon watch, helpless, pinned down onto the walls by the Advisors' psionic powers, Dog jumps through the roof and attacks the Advisor before it can do the same thing to Alyx and Gordon, severely injuring it causing both Advisors to flee. Alyx cries over Eli's body as Gordon passes out and the credits roll.
