The Doctor is infected with an intelligent virus; to combat it he and Leela create clones of themselves (!) and shrink the clones (!) so they can fight the virus (!). ( )

An adventure with the Fourth Doctor and Leela, this story also introduced K9 to the Doctor Who universe. In the far flung future, mankind has traveled into space and set up colonies on far off worlds. On a routine expedition to the refueling base on Titan, a moon of Saturn, a crew on a space shuttle comes into contact with a mysterious cloud that is floating through space. Upon contact, the crew become slaves to the Virus and overtake the base in order to convert it to a breeding tank for the Hive. Meanwhile, the Doctor and Leela are in the area and also come into contact with the cloud, and this time the Nucleus takes over the Doctor because of his immense intelligence.

Leela and the Doctor go to the Foundation in hopes of curing the Doctor, only to discover that they are going to have to go on a journey into the Doctor's actual mind in order to rid it of the Nucleus. However, they unknowingly release the Virus into the world and it takes some cunning on the Doctor's part, Leela's hunter instinct, and K9's assistance to defeat the Virus and prevent the Hive from hatching.

I haven't seen this episode, but I'm fairly sure that I could just read right along with what I'd be watching on screen. It certainly doesn't feel like the story was embellished in any way. Part of me almost doesn't want to see the episode either, because I'm fairly sure the limited-budget special effects will certainly not live up to the picture in my mind of how this entire story played out. ( )

http://nhw.livejournal.com/1007902.html

Doctor Who and the Invisible Enemy is a case where the novel is basically written as if watching the TV story and writing down what happens on screen. Actually that's not quite fair; the fact that we cannot see the embarrassingly awful monster in the last episode makes it easier to concentrate on the plot, which makes more sense and is a better sf story than I had realised. ( )