I can't believe this hasn't gotten more attention
Half-life 2: Episode 3 Proof of Concept
A downloadable mod
Map name: Half-Life 2 Episode 3 Demo
Authors: 'GamerGazz' and 'The Beach'
The aim of this map is to create a proof of concept showing a small section of the story synopsis as released by Marc Laidlaw. This map was built using existing Half-life 2 assets within the Source Engine for consistency between all of the Half-life 2 series of games.
To play the submission:
1. Install HL2:EP2
2. Place the .BSP file into your HL2\EP2\Maps\ directory
3. Open the console from within HL2:EP2 and enter the command, 'map borealis_hl2_ep3_demo.bsp'.
Note: You may need to enable the console from your game options. To do this go to Options, Advanced, and then tick the box for 'Enable Console'. Press ¬ to open the console and enter "map borealis_hl2_ep3_demo.bsp" to start the level.
Upon download, extract the zip file to your HL2 Episode 2 maps directory. Load using the 'map' command from within the game.