Michael Potts is evacuated from London to Devon during World War II. He is looked after by Mr and Mrs Shadrick, a middle aged couple who live on a farm. Mrs Shadrick is a serious woman with a list of house rules all of which Michael is determined to obey, except for one, rule number 9, 'under no circumstances will you go up in the attic'. Bored and curious Michael ventures up to the forbidden attic to find an old man, dressed head to toe in a soldiers uniform who introduces himself a Dawson, just Dawson.