No. The plot was at first amusing, but it doesn't stand up to much scrutiny.<br /><br />Remember how vastly different things became in "The City on the Edge of Forever"? One person lived who should have died and "poof!" no Federation at all. Given the violent nature of the mirror universe, how many people died who should have lived? Keeping that in mind, how many children were never born who should have lived? Now given all that, what are the odds that there exists a mirror Enterprise with Kirk, Spock, Uhura, McCoy, and the whole rest of the exact same crew? Zero, that's what. The histories would be so different that you'd never have assembled the exact same crew in mirror universes. They wouldn't be mirrors at all. <div class="Discussion_UserSignature"> </div>