Roman/Nazi-style military salutes were used by all crew members to show loyalty. Officers could advance rank by killing superiors who they thought were incompetent. Officers were barbaric aboard starships and discipline was enforced through torture - crew members carried agonizers and ships were fitted with agony booths. In the 23rd century, during the original series of Star Trek, humanity had enslaved dozens of alien worlds and formed the Terran Empire instead of the United Federation of Planets (as exists in the main Star Trek universe). Uniforms are often more suggestive, such as women baring midriffs, and men with tighter pants. Whereas the Star Trek universe usually depicts an optimistic future in which the Earth-based United Federation of Planets values peace and understanding, episodes set in the Mirror Universe show the galaxy to be marred by continual warfare, with compassion seen as a liability. Kirk and a Spock), but their personalities are, on the whole, much more aggressive, mistrustful, and opportunistic. The characters in the Mirror Universe are generally the same as the characters in 'normal' Star Trek continuity (for example, it has a James T. 8 Parodies, homages and similar stories.5.2 'The Mirror Universe Saga' (DC Star Trek comic, 1984-85).
