"The Alternative Factor" is the twenty-seventh episode of the first season of the American science fiction television series Star Trek.
Science Officer Spock informs Captain Kirk that the gravity pull of the planet fluctuated to zero and the surrounding space momentarily "winked" out of existence.
Back on the ship, Lt. Masters informs Captain Kirk that the mysterious disturbance has drained the dilithium crystals in the warp drive.
Starfleet fears that the disruption may be a prelude to an invasion and has ordered all ships except the Enterprise to leave the area.
Lazarus periodically fades in and out of the universe, encountering a lookalike enemy in a "dimensional corridor", creating an energy wink.
Lazarus explains to Kirk that he is a time traveler; his spaceship is actually a "dimensional corridor gateway"; and the planet below was once his home world.
The Anti-Lazarus admits to stealing the Enterprise's dilithium to prevent his doppelganger from using it to invade the anti-matter universe outside the dimensional corridor.
He informs Kirk that his people believed two universes existed, and when his matter counterpart learned about it, he went insane and became obsessed with destroying his doppelganger.
[2] The special effects for the extra-dimensional "winking" episodes were achieved by superimposing a moving photograph of the Trifid Nebula over the action.
Club, 42 years after its initial debut, gave the episode a 'C−' rating, describing the plot as "baffling", "unrewarding" and poorly paced.