The Kidnappers

Dr. Ann MacGregor is kidnapped by a time traveler from the future that came from the star Canopus. Dr. Raymond Swain finds the coordinates he had used and is authorized by General Kirk to send Doug and Tony to rescue Ann. The scientists are received by the Curator of Canopus that tells that they are in the year 8433 AD of Earth and he used Ann as bait to bring them to his planet. Further, he intends to drain the brains of Doug and Tony to learn their experience and increase his knowledge. When the time tunnel personnel tries to bring the trio of scientists back, the time traveler Ott returns to the complex and steals the space-time converter and the tunnel is useless. Doug and Tony seek the apparatus and try to send Ann back using the teleport chamber of the aliens.

"The Kidnappers" is a silly but funny episode with some of the most imbecile lines and situations I have ever seen in this series. For example, Ann advises Tony to not press the buttons without knowing what could happen like the scientist was a child; or Doug telling the Curator that they have not swelled the pills; or why the Curator did not follow the same procedure he did with Hitler with Doug and Tony waiting for the last moment of their lives to drain their brains. My vote is seven.

Title (Brazil): "O Túnel do Tempo" ("The Time Tunnel")