Catweazle, an 11th century magician, is conjuring in his cave when his enemies suddenly burst in. He flees, casting a spell to make himself fly. However, something goes wrong because the spell transports him to the 20th century instead.
In an attempt to return to his own time, Catweazle's dubious powers land him on top of the church spire. After being rescued by the vicar, Catweazle has an encounter with the vicarage telephone.
Broomsticks are being stolen. Police Sergeant Bottle believes that they are being used for witchcraft and that Sam is the culprit. Carrot enlists Catweazle's help to free him.