The idea of returning to the mirror universe in
Enterprise was first suggested by
Judith and Garfield Reeves-Stevens. In "
Mirror, Mirror", the tantalus field was used on several occasions and was thought to be a
disintegrator. The Reeves-Stevens proposed that it could be explained that instead of killing its victims, the field instead transported them back through time to a
penal colony in the main universe. The
Enterprise would then come across the penal colony, meeting
Tiberius, portrayed by
William Shatner.
[5]
Tiberius would seek to use the transporter aboard the
Enterprise to return to his own universe, but discovers that it has not yet diverged from the main universe and does not exist. The episode would then have explored the creation of the mirror universe through actions by Tiberius and Captain Archer. The storyline was pitched by Shatner, who had worked with the Reeves-Stevens on the
Shatnerverse series of
Star Trek novels, to
Manny Coto,
Brannon Braga and
Rick Berman.
