We'll probably never get another Half-Life game, but where official Valve canon fails us, series writer Marc Laidlaw does not. The former Valve employee who wrote Half-Life, Half-Life 2, and both of Half-Life 2's episodes has shared a fictional letter on his personal site that, once you swap around some proper nouns, sure reads like a plot summary of where the series would have gone after the events of Half-Life 2: Episode 2.
Dubbed "Epistle 3" and penned by Dr. Gertrude Fremont, it tells the exciting story of her travels to Antarctica and the discovery of a powerful device capable of traveling through time and space called the Hyperborea. Dr. Fremont and her companion, Alex Vaunt, fly the Hyperborea into the heart of enemy territory, where they intend to detonate it. Just before that happens however, a sinister figure, Mrs. X, steps out of the shadows and steals Alex away. It looks like Dr. Fremont is doomed, but is then pulled through dimensions by the Ghastlyhaunts and saved.
She ends her letter by saying that she does not recognize a place she once knew, and that the resistance will either succeed or fail without her. Well, not too hard to read between the lines there, is it? She says to expect no further correspondence, and that this is her "final episode."
Of course, I'm no Marc Laidlaw, and my summary hardly does the story justice. You can read the original version of the letter on his site, or read a version where the names and places have been changed to match the Half-Life series characters on Pastebin.
Laidlaw referred to the story (with what I can only imagine as the biggest wink-and-nod in human history) as "fanfic" on Twitter, calling it a "a genderswapped snapshot of a dream I had many years ago." And while it's true that this isn't officially what happens to Alyx and Gordon, it sure seems like this is the direction Valve was going at one point. Laidlaw's account even matches well with some supposedly leaked concept art for Half-Life 2: Episode 3, which appeared on the web in 2012.
The terms "Half-Life 2: Episode 3" and "Half-Life 3" have been used interchangeably to refer to the next, highly-anticipated chapter in the Half-Life saga. And while we may never get a game bearing either of those labels, I'm okay with treating Laidlaw's account of what happened as the final nail in the coffin. Rest in peace, Gordon Freeman. You done good.