I loved this episode. This episode shows us Dr. Smith not as the cowardly, comical character that he would soon become, but as a murderous, deranged saboteur that will stop at nothing to have his way. He monkeys with the rockets that John Robinson uses in an attempt to kill him. After John has crashed, and presumably been killed, on the planet, Don and Maureen tell the others to strap in while they land the ship and plan to search for John. Smith gets the robot to act as a henchman and threatens to have everyone aboard killed unless they abandon their plans to land and return immediately to earth. West tricks Smith, but Smith has one more trick up his sleeve. After forcing Smith into a freezing tube, they realized that Smith had done something to the ship's controls. The result is an exciting crash landing sequence that is second-to-none. An illogical thing about this episode:
When John Robinson is found, he explains that he found some fuel and got his jetpack working about 100 feet up from the ground. At that distance, he'd have been going so fast that he'd have been smashed to smitherines on impact with the ground even if he got the jet pack working! They should have had him say 1,000 feet up, or maybe even 10,000.
One question about the series in general: I have always wondered why the writers had Smith wanting to return to earth so badly. Of all of the characters, I would think he would have been anxious to see to it that they remained lost and not return to earth. After all, think of the charges he would certainly have faced! He was a traitor and a saboteur. These days, he'd have been labeled a terrorist. Upon returning to earth, he would have faced all of those charges! If anyone had motive to stay away from earth, it was Dr. Smith.