Was the new expansion a decision to go back and re-explore the territory of Doom 3 a little more in this format rather than create a Doom 4 for that?

"It kind of evolved, we had some parallel development time so we actually started on the expansion 16 months ago so it gave us a good 6-8 months of parallel development" stated Matt. "And working with Nerve (Software), which is right down the street from us, we had all this opportunity to work a couple of story hooks. For people who pay attention to the story they will notice some of the characters in the expansion were hinted at in the original story line. And also, with just the evolution of the weapons and stuff, we didn't have a conscious decision to 'hey, let's keep this from Doom 3 and put it in the expansion,' it just kind of evolved from its own thing. We knew we wanted to give the player more of the fast-paced action, more of the horror elements, more of the tension, but then wanted to throw a couple of new things at the player."