Enemy at The Gate (Stargate Atlantis) - Production

Production

Even though "Enemy at the Gate" is the final episode in the series, its production number was 519, leaving 520 for "Vegas", which was filmed on location in Las Vegas, Nevada. The shooting of "Enemy at the Gate" overlapped with "Vegas", which was not unusual as Atlantis used to film multiple shows at the same time during its run. The VFX budget was over half a million dollars, only being seconded by "The Daedalus Variations" for the most VFX dollars spent on an episode in season 5.

Many of the happenings in "Enemy at the Gate" were originally planned because the episode was the 100th episode as well as a season finale. When the writers learned of the cancellation, they found the events even more appropriate to serve as series finale. In writing the episode, the writers had to take a lot of backstory into account. It needed to be addressed that the Atlantis characters did not necessarily know the recurring characters from the Stargate franchise such as Major Davis. Stargate Atlantis was originally intended to be continued by a two-hour movie, but MGM filed for bankruptcy in 2010 and shelved the Atlantis film indefinitely.

Because it was not very clear to the audience, Paul Mullie explained that the "Todd" character "is very much back to being a full-fledged human life sucker at the beginning of this episode", and gave this as the reason why Sheppard appears so cruel to "Todd". The original first scene included explanatory dialog, which was cut when SciFi asked for a Keller scene earlier in the show so that her appearance in the last third would not be as jarring. New explanatory dialog that Mullie added to the first act of the script was filmed but later cut for time. There are plans to make the trimmed and cut scenes available in a special extended version, likely to be released on DVD. Brad Wright temporarily considered to use the wormhole drive as a set-up for a similar drive in Stargate Universe, but instead, this technology is planned to appear as part of the story for the Atlantis film.

The last scene's possible connection to Star Trek is pure coincidence. The producers had wanted the city to come down on Earth near a recognizable landmark, as to be different from the previous five years of the show where Atlantis was always located in the middle of the ocean. Martin Gero and Carl Binder were insistent that it should be the Statue of Liberty, but the geography was not plausible enough for leaving the city cloaked for any length of time without anyone noticing and/or getting killed. So the producers settled on San Francisco and the Golden Gate Bridge.

Although the producers knew of Don S. Davis' (George Hammond) heart problems, his death "came as a total shock" to them. They originally talked about just showing an "in memoriam" card at the end of the show, but as Davis's death also meant the end of the character's arc, they decided to acknowledge it by renaming the ship.