Andy Briggs 
Monsterville [EPUB ebook] 

Ramble is dropped off by his mum to visit his Grandpa in the retirement home. But this is no ordinary smelly old retirement home – this is a MONSTER retirement home! And this is not going to be another dull evening with Grandpa… A sinister construction company is determined to destroy the house and grounds – even with all the monsters inside! They want a secret hidden beneath the home… and they’ll do anything to get it…