S2·E29 The Astral Traveler

Dr Smith and Will become trapped in a cave during a cosmic storm. Will is accidently pulled through a cosmic time warp, and ends up on Earth, in Scottish castle. He meets a headless ghost called Hamish who was beheaded at the Castle. Hamish is trapped there due to the callous crimes he has committed. They rest of the family manage to get Will out, but Hamish follows him. They decide to re-create the time warp, and send Hamish home, and with him Dr Smith, carrying star-charts and maps so that he may send a rescue mission to save the Robinsons. Upon re-entering the warp, Dr Smith drops the charts, and Will runs after him to give them to him. They are both taken. When they reach the castle again, Dr Smith and Will realise that they are not in their time. Also, Hamish becomes angry when he realises that Dr Smith is a liar, and has no intention of helping the Robinsons. As an act of reveng he sets out to destroy Dr Smith. In the end, Will and Dr Smith return to the planet, and Ha