The Enid Blyton Secret Series 1997 S01E04

Episode: The Secret of Moon Castle. Thaddeus reveals that his application to adopt Jack has been successful. The family take a short break in an Irish castle run by the eccentric Ma Moon and her mysterious son Fin Bar to celebrate. Charlotte proposes to Thaddeus - but the next day he has disappeared... Charlotte goes off in search of Thaddeus. Ruby finds herself a reluctant participant in Ma Moon and Fin Bar's quest; the search for eternal youth! The children notice that she has suddenly become full of energy, which they do not know is due to her being secretly given a potion by Ma Moon and Fin Bar.... The children encounter a ghostly figure on horse back and all are convinced that the castle is haunted. The children decide that someone is trying to scare them off. Charlotte finds Thaddeus - much to his annoyance.