After the destruction of the Klingon moon Praxis leads the Klingon Empire to pursue peace with their long-time adversary the Federation, the crew of the USS Enterprise must race against unseen conspirators with a militaristic agenda. It is the sixth feature film based on Star Trek, and a sequel to the 1966–1969 Star Trek television series. Taking place after the events of Star Trek V: The Final Frontier, it is the last film featuring the entire cast of the original series.

References:
https://en.wikipedia.org/wiki/Star_Trek_VI:_The_Undiscovered_Country