- Star Trek: The Motion Picture
- Star Trek II: The Wrath of Khan
- Star Trek III: The Search for Spock
- Star Trek IV: The Voyage Home
- Star Trek V: The Final Frontier
- Star Trek VI: The Undiscovered Country
- Star Trek Generations
A criminally ill female sentenced to the penal colony on Tantalus V. By 2268, Lethe had received treatments on the neural neutralizer which gave her an eerily soporific demeanor.