The Intruder (Oxford Children's Modern Classics)

There was something weird about the stranger, something that Arnold didn't like. He made him feel uneasy and suspicious. Always poking his nose in where it wasn't wanted and winding Arnold up. All Arnold wanted was for him to go away and leave him alone but there was only one way he could stop
him...

This exciting story was shortlisted for the Carnegie Medal and was the winner of the Silver P.E.N. Award (Children's Section).