Clarence Wilkinson and Jenny Matheson make some unofficial enquiries about the wellbeing of a soldier based at Overton in Hampshire who although only slightly injured in a road accident has been posted to Wales to convalesce. It is 1941 and the young man's father believes that he is not being told the whole truth by the military authorities. The discovery of an excellently forged ten-shilling note points to the possibility of the existence of a Nazi counterfeiting operation in the Overton area. Jenny goes undercover as a school secretary at the girls' boarding school adjacent to the military site while Clarence follows a line of enquiry by the murder of an army deserter in Hackney who was in possession of a substantial quantity of the brand new forged notes.