With only a week to go until Portal 2 warps into stores (and maybe even less if those ARG rumours prove correct), excitement for Valve's next game has hit fever pitch. But there are still some unanswered questions. How exactly does Steam integration work on PS3? Why wasn't Steam brought to Xbox 360? And where on Earth is Half-Life 2: Episode Three? GamerZines sit down with Valve programmer Jeep Barnett to get to the bottom of it.