The Mysterious Castle is set in Cornwall in 2014.  It tells the story of three brothers and three sisters.

The three sisters who are triplets go out to play and despite being told my mum to stay close to the house, the girls decide to venture further and end up lost in the woods.

Mum then sends the boys out to find the girls, not realising they are lost.

What happens next is an adventure for the family.   As mum and dad search anxiously for the children, the brothers and sisters are fighting for survival at the hands of the Ghost Skeletons.