Summary
Star Trek Generationsfeatured an echo of Guinan (Whoopi Goldberg) in the Nexus after she had left, but the film’s villain didn’t get the same treatment.Generationswas one ofStar Trek’s most ambitious film projects, bridging the gap between theStar Trek: The Original SeriesandStar Trek: The Next Generationmovies. The film’s plot mainly focused onTNG’s cast of charactersbut incorporated characters fromTOS, including Captain James T. Kirk (William Shatner), in some surprising ways.
The plot’s driving force wasthe Nexus, an energy ribbon and portal to an alternate reality that granted the person inhabiting it their dream life.Generations' villain, Dr. Tolian Soran (Malcolm McDowell), attempted a dangerous plan that would have destroyed an entire planet to return to the Nexus, prompting the crew of the USS Enterprise-D to try and stop him. During the film’s climax,Captain Jean-Luc Picard (Patrick Stewart)was caught in the Nexus, where he encountered a version of Guinan who had also been a previous resident. However, the fact that only Guinan had a Nexus echo raises questions.

Every Star Trek Movie In Chronological Order
With 13 entries in the Star Trek movie series from 1979-2006, there are a couple of ways to watch the films chronologically.
Why Guinan Was In The Nexus In Star Trek Generations But Not Dr. Tolian Soran
There are several possibilities as to why Guinan’s echo stayed in the Nexus
Since both Guinan and Soran were residents of the Nexus, it doesn’t make sense why Guinan left an impression while Soran did not. However, there are a few explanations why this might be the case. For one thing,Guinan has always been shown to have unexplained abilities related to telepathy and understanding of space-time. Although all El-Aurians may have these abilities, Guinan was and is the most well-established member of her species. She may possess powers that not all El-Aurians share, which could explain how she was able to leave an echo so strong it could talk to Picard.
Guinan’s powers included the ability to tell when the events of a timeline had diverged, something that was useful in bothTNGand her reappearance inStar Trek: Picardseason 2.

The other possibility is thatSoran did have an echo in the Nexus that Picard never met. Guinan’s echo likely appeared to Picard because of their close relationship, something he did not share with Soran. It’s entirely possible that all people who inhabit the Nexus leave some kind of impression even if they escape, andSoran’s obsession with the Nexuswas certainly strong enough to support the idea. The fact that Picard didn’t encounter Soran’s echo may have just been luck on his part. However, the simplest and only confirmable explanation has nothing to do with Nexus' in-universe lore.
The Real Reason Why Guinan Was In Star Trek Generations’ Nexus
At the end of the day, only one possibility is true
Ultimately, the real reason there is no explanation for Guinan’s echo comes down to the fact that the Nexus was poorly conceived.Although the Nexus was a central part ofStar Trek: Generations, it was never fully fleshed outor explained in a way that made sense.Generationsneeded some way for Captain Kirk to meet Captain Picard, which was ultimately the only purpose the Nexus served. Using it to hold Kirk in suspended animation until the 24th century was the Nexus' reason for existing, andGenerations' creative team hand-waved a lot of its other more ridiculous qualities.
Additionally, the Nexus has never made an appearance in anotherStar Trekmovie or TV show, making it an anomaly in the timeline and leaving no room for its further exploration.

While suspense of disbelief makes it possible to watchStar Trek: Generationsand understand the Nexus, it doesn’t hold up under scrutiny. In fact,Guinan’s echo isn’t even the most important unanswered question about the Nexus, given its connection to Kirk and his death. Additionally, the Nexus has never made an appearance in anotherStar Trekmovie or TV show, making it an anomaly in the timeline and leaving no room for its further exploration. If another project ever decides to bring the Nexus back, the franchise would do well to explain some of its more obscure qualities.