Nightmare Stairs

I'm falling - falling down steep, narrow stairs - if I hit the bottom asleep, I know I'll never wake. Every night Kirsty wakes up screaming. Every night she has the same terrible nightmare - of falling downstairs. But does she fall? Or is she pushed? Then Kirsty discovers that her grandma died falling downstairs and she begins to wonder: is the dream hinting at a dark secret in her family? She has...