“The Deadly Years” just like its theme of old age seems to drag on a little although the sub plot of a competency hearing for Captain Kirk was quite entertaining. Otherwise, we have at best two average episodes that you won’t miss in your collection.
Rating: 4 / 5

Caught in the beginnings of an ion storm, Kirk, McCoy and Uhura interrupt their negotiations with the Halkans for dilithium crystals, to return to the U.S.S. Enterprise. Scotty beams the landing party aboard as a burst from the storm hits the starship. The transporter short-circuits, sending Kirk, McCoy, Scotty and Uhura into a parallel universe. In this world, they soon discover the “Galactic Empire” is maintained by fear and assassination. Now, aboard the parallel version of the U.S.S. Enterprise, the four must find a way to remain undetected until they can return to their own universe.

Meanwhile, the I.S.S. Enterprise versions of Kirk, Scott, McCoy and Uhura have been beamed on board the positive U.S.S. Enterprise. Their behavior is so different from their counterparts that Spock immediately realizes something is wrong. He puts the four in the brig until the transporter could be checked and repaired.

On the I.S.S. Enterprise, the parallel Chekov is foiled in an attempt to assassinate Kirk. When Kirk refuses to give an order to destroy the Halkans, who have refused to give up their dilithium crystals, the bearded Spock becomes suspicious.

The Imperial Starfleet sends a secret message to the bearded Spock, telling him to kill Captain Kirk and assume command of the starship I.S.S. Enterprise. Finding an unexpected ally in the bearded Spock, Kirk continues to stall while his three comrades gather the information needed to send them back to their own universe. Scotty tells Kirk that if the four don’t leave in three hours, they will be trapped forever in the mirror universe.

The bearded Spock has no desire to become captain, and therefore a mark for assassination. Along with Lieutenant Marlena Moreau, who wants the parallel Kirk back because she is “the Captain’s woman,” they help return the four U.S.S. Enterprise officers to their own world. Before he goes, Kirk talks to the bearded Spock, telling him the advantages of a Federation-system over the anarchy of this universe. Spock seems almost convinced that he should in fact get rid of his Kirk, seize control of the I.S.S. Enterprise, and manipulate the Imperial Starfleet into working toward a more civilized universe. With the dimension barrier about ready to collapse and seconds to spare, the small U.S.S. Enterprise crew beam on their own ship. Kirk can only hope that the parallel Kirk will find changes from the bearded Spock.

“The Deadly Years”

On the way to Starbase 10, the U.S.S. Enterprise stops to deliver supplies to the colonists of Gamma Hydra IV. A landing party, consisting of Kirk, Spock, McCoy, Scott, Lieutenant Galway and Chekov beam to the planet’s surface. They find that accelerated aging has taken place, killing most of the colonists. Chekov is terrified when he discovers the first body. The only survivors, an elderly couple who claim to be in their twenties, die shortly after meeting the U.S.S. Enterprise crew. When the landing party returns to the U.S.S. Enterprise, the aging acceleration begins to affect the entire crew … except Chekov, who remains unaffected. While Kirk wants to remain in orbit around Gamma Hydra IV until a cure can be affected, one of his passengers, Commodore Stocker, wants to proceed to Starbase 10 where he feels the best medical aid can be found.

Each person on the U.S.S. Enterprise begins to show the effects of old age and soon Kirk is unable to command, as are Scotty and Spock. Command falls to Commodore Stocker, who, while an efficient desk officer, has no deep space training. Thinking he will save time, Stocker plots a course through the Romulan Neutral Zone on his way to Starbase 10. The Romulans are waiting and begin an attack.

Stocker, panicked and inexperienced, has no idea what to do. As the U.S.S. Enterprise is surrounded, McCoy comes up with an antidote to the aging sickness … adrenaline. Chekov, he explains, wasn’t affected because his fear at finding the bodies on Gamma Hydra IV had already kicked his natural adrenaline into high gear.

McCoy restores Kirk to normal in time to save the U.S.S. Enterprise by reusing his famous “corbomite” bluff and telling the Romulans that the U.S.S. Enterprise would destroy anything within a 200,000 kilometer radius. McCoy distributes the antidote and restores everyone to their normal state.
Rating: 4 / 5

1st Officer Spock: “Terror must be maintained or the empire is doomed. It is the logic of history.”

Captain Kirk: “Conquest is easy. Control is not. We may have bitten off more than we can chew.”

Rating: 5 / 5