The Enid Blyton Secret Series – Plot Synopsis – Book Four: The Secret of Moon Castle

The Enid Blyton Secret Series – Plot Synopsis – Book Four: 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 Bar¹s 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.

Jack and Laura find a secret passage which leads to the tower. They discover the laboratory where Ma Moon and Fin Bar have been conducting their tests..


They soon discover that for all the hospitality, they are actually part of a dangerous experiment. All the ghostly events are designed to throw them off the scent.

Interwoven with Œthings that go bump in the night¹, a portrait which Œcomes alive¹ and the mischievous disappearance of the family’s belongings, Thaddeus, Charlotte and the children finally foil the bizarre plans of Ma Moon and Fin Bar.

In the midst of the celebrations (and much to their delight) Peggy, Mike, Laura and Jack discover that Thaddeus and Charlotte are to be married after all…