‘Seriously iconic’ would be one way to describe this classic episode. ‘Out there’ would be another.
Feeling homesick more than ever, Dr Smith resets the ‘astrometer’ to head the Jupiter 2 back to Earth. Don struggles to stop him and in the process the navigation equipment is damaged and the ship’s reserve fuel supply is accidentally jettisoned into space. Professor Robinson then plots a new course for an intergalactic fuel barge.
Meanwhile, while playing a game of chess against Will, Smith sees a green female alien floating outside the main deck view-port. The robot determines she is from the People of the Green Mist and says she is in love with Dr Smith and wants him to come away with her. She speaks, but mostly not in English so the robot translates.
Smith fools Penny into again altering the course of the astrometer. Once more they are headed in the direction of Earth. Dr Smith then goes on a spacewalk with the ‘Girl from the Green Dimension’. The robot advises he has now had time to ‘calculate this creature’ and that –
“She and her kind feed upon atomic fuel. She has followed us for our fuel supply. Dr Smith thinks he is in love. She has created that state of mind in order to get fuel from us.”
Because Smith is outside the spaceship they miss their turn for Earth. Don goes out to bring him back in. They then pick up a radio message from Alpha Control on Earth. This is the first time the Robinsons have heard from Alpha Control since the debut episode of Season One. They soon realize they are again headed off course and away from Earth’s orbit. The episode concludes with an exchange between Will and his father –
Will: “Dad, where are we going now?”
Professor Robinson: “We’ll know when we get there son”.
Ps. The actress who so memorably inhabited the role of the green floating alien was Vitina Marcus.
Now aged 82, after her acting life concluded around the late 1970’s, she went on to a career in real estate.