A delightful Children's Film Foundation film. Four children (Pierre Bedenes, Lucinda Jackson, Peter Bartlett and Robert Bartlett) are allowed off to sea on their own but run into trouble. They eventually land on tiny Monk's Island which, they are told by Eli (Conrad Phillips), is now uninhabited... except for the ghost of a monk.
While the search for the children continues news comes in that a convict (Jerold Wells) has escaped gaol and has been seen in the area. Meanwhile why does Jacob (Ivor Salter) seem to want to discourage Eli from checking Monk's Island? Meanwhile on the island the children (who seem to be able to find anything they need including string in abundance) start seeing the ghost of a monk...
A wonderfully nostalgic film when kids could be left to play all day on their own, and when boys carried knives it was to help them make kites, stockades and other boy scout antics. The film is full of the sort of things that used to fascinate children like abandoned houses and mysterious tunnels in a simpler, more civilised age...