When I usually watch an Enterprise episode, I have to mute the opening song, which I cannot stand. But "In A Mirror, Darkly" (Season 4, Episode 19, Part 2) has different music (no singing) and visuals from the alternate universe of that episode. It was much better and very creative. I saw it on cable TV's H & I (Heroes & Icons) channel. I never saw that episode, but heard about it. I wish I'd seen Part I, as it was hard to figure out what had been set up.