Grandpa's Shed

Robert was almost ten years old, so things like make believe worlds and strange creatures were no mystery to him. He wasn't a complete baby, and realised that was just what they were, make believe. So when his Grandpa started to tell him stories about other realities and the weird and wonderful beings that inhabited them, he thought he was just being told made up stuff. That is, until he took a real look into Grandpa Kenneth's garden shed?.