Have you ever sat around thinking, "Gee, I wonder what's happening in the alternate universe? What is my evil counterpart doing right now?" Well, if you've ever wondered that in regard to Captain Archer and his squad, there's a treat in store for you. The latest episode to complete photography is the first of a two-part adventure taking place entirely in the parallel universe introduced in "Mirror, Mirror" (and reprised several times in Star Trek: Deep Space Nine), but contemporary to the NX-01.

The Enterprise sets have been redressed and the cast re-outfitted to convert them into members of the Terran Empire, the tyrannical counterpart to Starfleet and the eventual Federation. And a character who has kicked the bucket in the regular universe is still alive and kicking here: Maxwell Forrest — only this time, instead of being an Earth-bound admiral, he is sitting in the captain's chair of the evil Enterprise ... with a first officer named Commander Archer. Vaughn Armstrong makes a triumphant return to the set, happy that in science fiction, nobody really stays dead (Admiral Forrest, a recurring character, was killed in "The Forge").

The two-part episode is called "In a Mirror, Darkly," and both scripts were written by long-time staff writer Mike Sussman. As previously reported, Sussman describes the story as "a prequel to 'Mirror, Mirror' and a sequel to 'The Tholian Web,' two of my favorite episodes." All the action takes place in the mirror universe, without any interplay with the regular Star Trek realm. In "Part I," Commander Archer has gained information that a ship has been found in Tholian space that would give the Terran Empire a distinct tactical advantage over an interstellar rebellion. Archer tries to convince Captain Forrest to skip a rendezvous with the rest of the fleet and go in pursuit, but he refuses. So the ruthless Archer stages a mutiny and takes over Enterprise. It turns out the mysterious ship is an Earth vessel, from 100 years in the future.

That ship, we learn, is the U.S.S. Defiant NCC-1764, the Constitution-class starship which disappeared into a spatial interphase in Tholian space (almost taking Captain Kirk with it) in "The Tholian Web." That gave the set designers, art directors and construction crew the exciting opportunity to reproduce the Original Series bridge, down to the most intricate detail — though with subtle differences to make it the Defiant, such as the gold plaque next to the turbolift. This is the third time the TOS bridge has been depicted in a post-TOS show, but this is the first time it has been reproduced this completely, with a full three-quarter-round set. In "Relics" (Star Trek: The Next Generation) only about half of the full bridge set was built and shown on screen. In "Trials and Tribble-ations" (DS9) only small segments were used as background for the contemporary characters, the rest of the Enterprise bridge seen in repurposed TOS clips (though corridors and other sets were fully reproduced). This new set starts with the science station at the far left and goes all the way around to the viewscreen, with the captain's chair and the helm in the center.

But that's not the only interesting set design applied to this episode. The standing Enterprise sets had all the standard NX-01 logos replaced with the Terran Empire symbol, the same one from "Mirror, Mirror" with a vertical sword through the Earth. (Note: The term "Terran Empire" was actually introduced in DS9's "Crossover.") All the sets were redressed in various ways, but Sickbay in particular was made to look like a vivisectionist's lab, with dead creatures scattered about. The mirror Dr. Phlox is despicably evil — in one scene he is dissecting a still-breathing animal. Aside from the set dressings, the lighting was arranged differently to give the scenes a darker, more ominous feel.

There was one new Enterprise ship set: an Interrogation Room, complete with an "Agony Booth" as seen in "Mirror, Mirror." Turns out Phlox and "Major Reed" had something to do with its invention. Sorry, mirror-Chekov.

All the principal actors were given a makeover for a harsher, or at least alternate, look. For instance, Scott Bakula's hair was dyed black; Jolene Blalock's hair was lighter and longer; Linda Park got a heavy dose of eye makeup (she's got Marlena Moreau duty); and Connor Trinneer had half his face covered with radiation burns, from years of exposure to a less-than-code warp reactor (with that and his haircut, he might remind you of Captain Pike in "The Menagerie").

The evil-universe uniforms follow the same pattern as "Mirror, Mirror." The blue NX-01 jumpsuits were embellished, for the males, with leather straps and weapons belts (everyone carried a dagger), along with the Terran badge and medals as appropriate. The women had their jumpsuits radically altered with a very revealing bare midriff. Phlox's outfit was a black leathery number to give him a Dr. Mengele quality (the suit was so thick and rigid John Billingsley couldn't sit down in it). In this dimension Travis Mayweather is a MACO sergeant, so Anthony Montgomery wore altered fatigues.