I believe that was "The Daemons." The Master had become the vicar (Mr. Magister) of an English village("The soul is an out-of-date concept...looking at it existentially...") He terrorized the villagers and ordered them to celebrate May Day as usual. The Morris Dancers then went dancing into the town square and captured the Doctor. It was a stick morris they were dancing, if my memory is accurate. It's been a while, though, so I may not remember that detail quite right.

Okiemockbird (a.k.a. T in Oklahoma)