The Enemy Within

A transporter malfunction divides Captain Kirk into two people—one gentle, one mean and fierce.

Summary
While the Enterprise crew along with Captain Kirk are surveying the planet Alfa 177, geological technician Fisher slips down a rock, cutting his hand. Also, his uniform is smeared with a yellowish magnetic ore. He beams back to the Enterprise for treatment. During the transport cycle, Scotty detects a malfunction in the transporter. Fisher is eventually beamed aboard and reports to Sickbay, but the transporter appears to still be working correctly. Then, Captain Kirk beams up from the planet. He apparently materializes normally. When the transporter room is empty, another person materializes -another Kirk!. He has been split into two beings. The first Kirk to materialize blended all of Kirk's positive qualities -compassion, love, tenderness. The second Kirk blended all of Kirk's negative qualities -hosility, lust, violence.

Before the transporter malfunction is discovered, the evil Kirk roams the ship, demands Saurian brandy from McCoy, and attempts to rape Yeoman Rand. The evil Kirk is eventaully captured, but during the process he damages the transporter.

Eventually, Kirk acknowledges that his negative qualities are part of him and make him a successful Captain. But as he weakens, and begins to lose the ability to make decisions, he realizes that he needs his negative qualities to function as Captain -neither part can survive without the other.

Meanwhile, Sulu and the rest of the landing party are struggling to surive on the planet, as the temperatures continue to drop.

Finally, Scotty repaires all the damages to the transporter and Kirk'stwo halves are re-integrated. Feeling confident again as Captain, he gives the orders to beam up the landing party, saving them from freezing.

Regulars

 * James T. Kirk (played by William Shatner)
 * Spock (played by Leonard Nimoy)
 * Leonard H. McCoy (played by DeForest Kelley)
 * Montgomery Scott (played by James Doohan)
 * Hikaru Sulu (played by George Takei)
 * Nyota Uhura (played by Nichelle Nichols)

Others

 * Janice Rand (played by Grace Lee Whitney)
 * John Farrell (played by Jim Goodwin)
 * Fisher (played by Ed Madden)
 * Wilson (played by Garland Thompson)

Informtion

 * This episode was novelized in Star Trek 8 by James Blish

Related Stories

 * A sequel to this episode was featured in the Star Trek: The New Voyages short story, "Ni-Var".