Valve's modeler/animator Bay Raitt also joins the discussion at the very end, although the video ends during the conversation. The Half-Life 2 episodes having each introduced a new technology (the interaction with a well developed NPC, along with full implementation of the Source's HDR lighting system for Episode One large outdoor environments and high scale battles previously unseen in the Source engine for Episode Two), Episode Three's new technology would have potentially been this. The implementation of such character would be the starting point of implementing signing into Valve's games and give them the excuse to build a related technology and give easier access to video games for hearing impaired players. Then this person went away from Alyx to fight the Combine someplace else, and Alyx and Dog started signing with each other when they wanted to communicate without making noise or without other people knowing.

Newell suggests that before Alyx met Gordon, she had a crush on a hearing-impaired Resistance member, so she programmed Dog with knowledge of sign language so she could practice and easily communicate with them. This character is introduced in a video involving Gabe Newell and two interpreters discussing deafness and video games with a small audience of people with hearing loss, uploaded Augby a former University of Washington student, Samuel Sandoval, deaf as well. An unidentified deaf character was at one point slated to appear in the now-cancelled Half-Life 2: Episode Three.

Half life 2 episode tree