Earthfasts is a BBC children's drama series based upon the 1966 book of the same title by William Mayne.
Schoolboys Keith and David hear drumming under the hill on the moor near their homes, and set out to investigate. The hillside unexpectedly opens and Nellie Jack John, a drummer boy from the 18th century marches into the 20th. Bewildered and lost in a strange world, he decides to go back home.
David discovers that the candle the drummer boy left behind gives off cold rather than heat and does not burn down. Other strange things are happening - standing stones are moving on the moors, the ground is shaking and all the pigs have disappeared.