"The Powerful Enemy" is the first episode of the two-part
Doctor Who adventure "
The Rescue." Arriving on the planet Dido, the Doctor (
William Hartnell) and his fellow time travelers come across the remains of a crashed spaceship. Rescuing the two survivors, the Doctor endeavors to protect them and the TARDIS crew from the infamous murderer Koquillon. Written by David Whitaker, "The Powerful Enemy" originally aired on January 2, 1965. ~ Hal Erickson, All Movie Guide