The convention-goers were treated to a sneak preview of the upcoming mirror-universe two-parter, "In a Mirror, Darkly," which airs April 22 and 29. Before they showed clips, though, the writers explained the long history of the concept. "We had talked about doing a mirror universe episode ever since we got into Season Four," Coto began. "But then we had the possibility of getting William Shatner. Coincidentally, the Reeves-Stevens [who have worked with Shatner on several Trek novels] were a pair of writers whom I desperately wanted to bring on the show. And they, it turned out, had an idea for a mirror universe two-parter which would feature the return of William Shatner."
At past conventions, Shatner has spoken about a story concept which he himself pitched that was well received. But Paramount and Shatner failed to reach agreement so, as we know, Shatner wouldn't be making a guest appearance on Enterprise. However, the Reeves-Stevens couple (affectionately called "the Bynars" by their fellow writers) were now able to reveal what that pitch was.
"The idea was that the Tantalus Field was not a disintegrator, it was a humane way of dealing with prisoners, by sending them back in time to a sealed penal colony," Garfield Reeves-Stevens explained. "Enterprise NX-01 comes upon the colony — and Tiberius [mirror-Kirk] is there. Tiberius thinks, 'Finally, a ship with a transporter — I can get back to my own universe, my own time.' He basically goes on the NX-01, gets to the transporter, sets it to go back to the mirror universe — the mirror universe doesn't exist." "It hasn't been created yet," Judith elaborated. Garfield continued: "So Tiberius and Archer work together to figure out where the division point is between the universes, what point that one split off into the other. And as it turns out, Tiberius and Archer together are responsible for the creation of the mirror universe."
Coto recounted that Shatner pitched the idea to him, Brannon Braga and Rick Berman over lunch. They loved it, but Berman pitched an alternative concept, which was actually devised by Mike Sussman.
So Sussman explained that: "Shatner was going to be 'Chef' — an ancestor of Kirk. We would find out that at some point in the future the real Kirk got into trouble, got taken out of history. And Daniels would show up, he would grab Archer, he would grab Chef — who of course looked like William Shatner — and say, 'You have to go to the future and impersonate Captain Kirk in some important ceremony.' That was the setup."
"We pitched this to Shatner and there was a long silence," Coto continued. Well, since negotiations fell through, there would be no Kirk story, but they still wanted to do a mirror-universe two-parter. "We started bandying about ideas, trying to figure out a way to get our characters into the mirror universe, because as you all know in the Original Series the mirror universe was pretty much a first-contact situation. What do we do about that? We came up with a concept of doing the story solely in the mirror universe. As if you're watching a Star Trek: Enterprise episode coming straight from the mirror universe, including a whole new title sequence. And there's very little interaction with our regular universe.