The City on the Edge of Forever

Pretty well everybody seems to agree that "The City On The Edge Of Forever" was the very best episode of the original Star Trek series and what a lucky lady was Joan Collins to make her only Star Trek guest star appearance in it. Whilst tending a crew member with an injection from a syringe Dr. McCoy accidentally injects himself with its entire contents after the USS Enterprise jolts suddenly. This sends him temporarily mad & he then transports himself down to a planet that is under study for mysteriously warping space/time. Captain Kirk & Spock decide they will have to follow Dr. McCoy down on to the planet to try to rescue him. On this planet there is a time portal which is the cause of space/time disturbance & is capable of sending people back in time. In his crazy condition McCoy jumps through it & is transported back to planet Earth circa 1930. Kirk & Spock decide they too will have to risk going through the time portal to try & bring McCoy back. Here on Earth in 1930 the members of the Star Trek crew meet Edith Keeler (Joan Collins) who is running a home for down-and-outs. What then follows is a really excellent, creative story that has stayed forever in my memory.