Half-Life 3 is a running joke (or tragedy) among fans of the series who waited more than a decade for it to exist. With publisher Valve's business shifting to its Steam platform and key writer Marc Laidlaw leaving the company, the writing seemed on the wall. Turns out, though, it's on his blog: Epistle 3 is a lightly-cloaked synopsis (already edited by fans to remove obfuscating elements) of what was, in another world, the greatest game of 201A.
a Certain Sinister Figure appeared, in the form of that sneering trickster, G-Man. For once he appeared not to me, but to Alyx Vance. Alyx had not seen the cryptical schoolmaster since childhood, but she recognized him, instantly. "Come along with me now, we've places to be and things to do," said G-Man, and Alyx acquiesced. She followed the strange grey man out of the Borealis, out of our reality. For me, there was no convenient door held open; only a snicker and a sideways glance. I was left alone, riding the weaponized research vessel into the heart of a Combine world. An immense light blazed. I caught a cosmic view of a brilliantly glittering Dyson sphere. The vastness of the Combine's power, the futility of our struggle, blossomed briefly in my awareness. I saw everything. Mainly I saw how the Borealis, our most powerful weapon, would register as less than a fizzling matchhead as it blew itself apart. And what remained of me would be even less than that.
Laidlaw describes it as "fanfic": https://twitter.com/marc_laidlaw/status/900960760481726464
"Isn't everything you have written about half life technically a fanfic?" a twitter user asks.
"Psych!" Laidlaw replies.