10 Insane Doctor Who Episodes That Almost Happened
5. The Doctor Is Ordered To Kill His Companion
A lot of Doctor Who stories conclude with the Doctor and one or two companions combining forces to save the day. The Doctor will figure out the complicated science-y part, while the companion will bring the compassion, the human touch. They're an effective team because they each bring something different to the conflict at hand.
Rather than having them work together though, the proposed Fourth Doctor story Sealed Orders would've found the Doctor and his companion - Romana - at odds.
Described as a political thriller in which the Time Lords order the Doctor to kill Romana, this adventure was scripted by Christopher Priest, who most people will know as the author of The Prestige. The story was set to be very non-linear and complex, playing around with time paradoxes, an alternate Doctor, and multiple TARDISes existing inside one another, before concluding with Romana's departure.
Priest actually did end up writing this script, but it was never produced. Still, the idea of the Doctor chasing one of his companions - with both sides messing with time in order to stay one step ahead - sounds bloody fantastic. We don't know if this is how Priest's script played out, mind you, but we'd love to see something like this one day.