Grinny (Puffin Books)

Grinny (Puffin Books) by Nicholas Fisk. paperback edition. ISBN: 9780140307450.

Great Aunt Emma is no ordinary old lady. But why is she so strange? For a start, she just appeared, grinning, on the doorstep, as if from nowhere. Why have Mum and Dad never mentioned her before—after all, she is supposed to be Grannys sister, isnt she? Soon Tim and Beth start noticing more and more odd things about the great-aunt theyve nicknamed Grinny. And before long, they make a horrifying discovery. She isnt even human, shes as dangerous as a time-bomb and she has a fearful task to perform which involves them…