The final episode of the original network run of the landmark 1960s science fiction series, this installment of Star Trek begins with the Enterprise's Captain Kirk paying a visit to a distant planet to see Dr. Janice Lester, a former friend and fellow officer who is now ill. Dr. Lester's illness proves to be a ruse, however, when she attacks Kirk. When the felled Captain awakes, he finds himself the subject of a body-switching experiment that places his mind in the body of Dr. Lester. Meanwhile, Dr. Lester, in Kirk's body, has gone to enact her life-long dream of commanding a starship, a dream which was denied to her because she is a woman. Mr. Spock soon realizes the truth of Dr. Lester's masquerade, and he and the real Kirk -- still in Dr. Lester's body -- must prove their claims before they are executed at the false Kirk's orders. ~ Judd Blaise, All Movie Guide