10 Star Trek Twists You Never Saw Coming
2. The Bashir Substitution
In the fourteenth episode of Star Trek: Deep Space Nine’s fifth season, we find out that Doctor Bashir is being held prisoner in a Dominion internment camp. Moreover, he is still wearing the older, Voyager-style uniform. But wait, hasn’t he been on the Station this whole time? That’s right, the Bashir on Deep Space Nine is a changeling! The puzzled look on Worf and Garak’s faces is a mirror for the audience.
Inasmuch as we never saw this twist coming, it appears that the writers and producers had a little trouble with the continuity of the revelation, having to clarify a few issues after the fact. For the captured Bashir to appear in the older-style uniform, the switch with the changeling must have reasonably taken place before the switch to the new uniforms in the episode Rapture of the same season. If so, this would mean that the changeling version of Bashir performed complex neurosurgery on Captain Sisko and delivered the O’Briens’ baby, all the while taking part in social activities and completely duping everyone on Deep Space Nine. In retrospect, there are also some potential problems with the in-world timing of the interim events.
Furthermore, according to the Star Trek: Deep Space Nine Companion, Bashir actor Alexander Siddig was unaware of the changeling twist "until the last minute" and, hence, had not played the character any differently in the previous episodes. He was as surprised as the rest of us!