The Enterprise is in dry-dock getting refitted. It has a new Captain, Decker (Stephen Collins) who has taken over the reins of the ship from Admiral Kirk (William Shatner). Three years has passed since Kirk has been at the helm of the Enterprise. A disturbance has entered our galaxy and is headed towards Earth. It has taken out everything in it's path. Starfleet has given the ship back to Kirk to investigate what is coming.
Spock (Leonard Nimoy) has been on Vulcan to purge all his emotions using the Kohlinahr Ritual. When at the very last minute he is told to look for his destiny elsewhere. He heads for the Enterprise to see what this disturbance is all about.
Back in dry dock, the crew of the Enterprise is arriving aboard ship. Dr. McCoy (Deforest Kelly) arrives complaining about the transporter. Scotty (James Doohan) is in engineering trying to outfit the Enterprise to take off. Dr. Chapel (Majel Barrett) has been in charge of sickbay until McCoy arrives. Uhura (Nichelle Nichols) is back at communications. Sulu (George Takei) and Chekov (Walter Koenig) are back at their positions.
Scotty finally alerts the Capt. Kirk that the ship is ready. Kirk calls for all the crew to gather on deck to be told what they are up against. Traveling out of our solar system Kirk orders the ship to warp speed and throw it into a wormhole. Decker has to countermand an order of Kirk's that shows the lack of space time on the former Captain's part. A new member to the crew is Ilia (Persis Khambatta) a Deltan that Decker had a thing with years ago. Spock eventually catches up with the Enterprise and is welcomed aboard.
The ship reaches the cloud and realizes that there is more to this than just a gas cloud. There is something inside that is carrying out all the trouble.Ilia is probed by the alien and is beamed back to the center of the cloud. She will later come back as a probe.
The Enterprise will eventually find out the truth of the cloud and it enlighten us as to what we may be doing even now. The movie is very familiar to the TV show and thanks to Director Robert Wise many Trekkie's are very thankful. This was the first of 'Star Trek' movies, arriving in theaters way back in 1979. It is an enjoyable trip down memory lane and I know if you haven't seen it you certainly will want to.