She was there, and then she was gone. And before fans knew it, she was back again.

Dr. Beverly Crusher had been a part of "Star Trek: The Next Generation" from the first episode, but disappeared suddenly in the second season when Gates McFadden was replaced by Diana Muldaur. Although there were whispers about problems on the set, no one would ever confirm them — that is, until William Shatner brought a camera crew.

Continuing his string of successful documentaries highlighting the world of Star Trek, the former original series star looks at the first three years of TNG between 1987 and 1990 for a new documentary he calls "Chaos on the Bridge."

In a new clip from the film, which will be released digitally Aug. 1, Shatner casts a spotlight on the McFadden mystery, tying it directly to the ascension of Maurice Hurley as head writer for the second season. Hurley, who died in February at the age of 75, had issues working with McFadden, and it seemed to be mutual. And by the end of that season, Hurley was gone, as was Muldaur, and McFadden was back in sickbay.

Some of the story is shown in this clip of the documentary, released this week.

Shatner worked with Vision Films and Content Media to produce the film, and brought in many of the people who were a part of TNG in the 1980s. That includes Patrick Stewart, Jonathan Frakes, John de Lancie, Denise Crosby, Rick Berman, Brannon Braga and others.

The project has been in development for a number of years, something Shatner originally talked about under the title of "Wackydoodle." A trailer for the documentary features the late Hurley using the term, which Shatner told 1701News in 2013 was based on the "crazed and chaotic" environment on the TNG set. (video)

Original plans for the documentary called for it to be released in November 2013, in time for "Star Trek: Into Darkness," but instead, it will finally get its premiere at the beginning of August.

Shatner has shared that the focus of the film will be about the power struggles over the beginning of the show, likely painting a rather unflattering picture of TNG creator Gene Roddenberry.

You can see a trailer for the new documentary by clicking here.