It starts when the Enterprise picks up a signal from a spaceship. It is an old ship, from the 1990s! That is a very long time ago even now. Mr Spock says this was the time of the Eugenics Wars. I am only two years old so I am too young to remember the Eugenics Wars.
Captain Kirk beams across to the spaceship with Lt MacGyver.
Lt MacGyver is a beautiful girl and not a manny with a mullet and a swiss army knife.
They find Khan and his mannys and Captain Kirk wakes Khan up from having sleeps. They take Khan to the Enterprise and Dr McCoy finds out Khan is very strong. Lt MacGyver thinks Khan is handsome. Captain Kirk doesn't know Khan is a baddy yet because Mr Spock can't find any record of Khan in their wikipedia computer. He should have looked here.
Khan wakes up and captures Dr McCoy but Bones is not impressed.
"Well either choke me or cut my throat - make up your mind," he says, and "it would be most effective if you would cut the cat* artery, just under the left ear."
*I think this is what he said, but I'm not sure. I'm a cat, not a doctor.
Khan is impressed but he wants to speak to Captain Kirk because he's in charge.
Captain Kirk lets Khan read their internets for a bit so he knows things, and then Khan seduces Lt MacGyver. They go to dinner with Captain Kirk and Mr Spock, where Mr Spock tests Khan to see if he is a baddy and Khan gives himself away.
Now that they know he is a baddy Khan stops pretending to be a goody - he seduces Lt MacGyver more by being a baddy to her.
This makes her become a baddy on his side. For some reason.
Mr Spock finally finds out who Khan was - the leader of the baddys in the 1990s - and Khan is arrested but he escapes. Lt MacGyver helps him wake up the rest of his baddys on his ship and then they take over the Enterprise really easily. Everyone is captured, even Captain Kirk. Oh noes!
Khan offers the senior officers a chance to become baddys on his side. They all say no so he says he will kill Captain Kirk unless they join him, but they still say no. Lt MacGyver realises how bad Khan is. She goes and rescues Captain Kirk, and then Captain Kirk rescues Mr Spock.
They gas all Khan's mannys, but Khan escapes. Captain Kirk chases him and their stunt doubles have a fight. Khan is a strong man but Captain Kirk still wins because he beats Khan with a stick.
Captain Kirk puts Khan, his mannys, and Lt MacGyver in prison on a planet. Mr Spock wonders what their planet will be like in a hundred years.
That is the end of the episode.
This is a good episode because Khan is such a good baddy. He is strong and clever so he is a match for Captain Kirk, and he manages to get the girl on his side - which is usually what Captain Kirk does!
But the best thing about this episode is that without it there would be no Star Trek 2 Wrath of Khan (which is my best film ever!) because Khan would not be angry at Captain Kirk if he had not been beaten in this story.