Marc Laidlaw recently released the ending to Half - Life 3, he is the retired writer of the series. Thanks to Jackathan for archiving it since Marc's website is down to overload of traffic, this is the post that is sending the internet into an uproar

Conclusion of Half- Life:
https://github.com/Jackathan/MarcLaidlaw-Epistle3/blob/master/Epistle3_Corrected.md