http://www.valvetime.net/threads/new-images-of-half-life-2-episode-4-return-to-ravenholm.243033/

Half-life 2: Episode 4 or Return to Ravenholm was a title developed by Arkane studios and eventually cancelled. Little of the game beyond concept art and an animation reel demo has been seen before now. All images are verified as work from Episode 4.

We've uncovered a couple images which show some in-game shots of the title which show new textures and models Arkane planned for the game. You may notice a HUD element saying 'Absorption' in the images, if you have any suggestions what that might be, we'd like to hear them!

More at the link.Shame it was cancelled.

Never realy got the big deal about Half-Life, am I missing something.

Saw this on reddit earlier. Pretty interesting, and done by Arkane? Huh. Too bad it'll never see the light of day though. I also think this is hilarious, even Episode 4 has official game screenshots and has been "confirmed"(despite cancellation), yet Episode 3 has neither going for it if I recall correctly.

My guess is that "Episode 4" was just a working title. Since Arkane was developing it and Valve has developed all Half Life titles up until this point, I think it was probably a totally separate entity.

Gabe doesn't know the number 3.

Since the game was being developed by Arkane, I doubt that he had any say in the game's development.