Can Jon find a ghostly horse that's been extinct for centuries? Jon is a lonely orphan who lives on a farm with his adopted parents. When they ask what he'd like for his birthday, Jon knows immediately: to see the Moropus, a prehistoric horse that's big and furry, with claws on its feet instead of hooves. According to legend, it haunts the lonely moors at a waterfall that is known as Horse Force because its gushing cascade sound just like a mare's whinny.   But there's 1 problem: If Jon wants to see the ghost of the legendary creature, he has to visit Horse Force at the stroke of midnight--alone. Can he get up the courage to go there all by himself in the dead of night? Luckily there is 1 friend who can help Jon--his faithful pony Whiskers!   This ebook features illustrations by Gavin Rowe and a personal history of Joan Aiken including rare images from the author's estate.