The Secret of the Treehouse

Charlie always wondered what has been hiding behind the doors of his grandad's treehouse. But his grandad would just say, 'THE TREEHOUSE IS A NO GO PLACE' and would not entertain any questions of that sort. Even though last year, Charlie was convinced he had heard footsteps echoing through the night from the broken window of the treehouse, his grandad reassured him, they were just the long branches of the old oak tree knocking against the old cottage.

His annoying, teenage cousin Eric, however, had a different theory, making up stories of an abominable old troll living in the treehouse, giggling viciously behind their bedroom window.

This summer, Charlie was determined to find the secret of the treehouse. But never in million years, did he expect, his curiosity would eventually lead him to the deepest darkest underground tunnels, caverns sculpted of the most beautiful limestone and peculiar hidden worlds, in search of the key to the Kingdom of Solis, whilst being pursued by Zoutarus - the sinister leader of the Graves of Ozaar.
...and little did he know, his journey would eventually lead him to uncover the truth about his father's disappearance.