Audrey by O.F. Walton

THERE were three houses the windows of which looked into the old churchyard. Audrey and her aunt lived in one, Stephen and his father in another, but the third had long been empty. The windows were covered with dust, and the spiders and beetles had taken possession of it, just as they had done of the old church. However, to the children's astonishment, when they came back from watching the swallows on Stephen's birthday, they saw that the window of the empty house had been thrown wide open.

"Who can be inside? Dare you go and look, Audrey?"