Half-Life 2: Episode 3 never saw the light of day, but a fan project, built on the leaked plotline, has now released a special Unreal Engine 5-built level for fans of the series.
Project borealis RSS
Project Borealis, a community effort for Half-Life 2: Episode Three has been in development for just under a year, but already has a first draft of the script and an in-engine teaser under its belt.