J.I.M. Stewart 
Avery’s Mission [PDF ebook] 

Bannerman is a schoolmaster on his way to Florence to do some research. On the plane, he meets a recent pupil, Avery Brenton, who is travelling to see his divorced father. However, Avery is young and naive and is being unwittingly used by his domineering mother. Bannerman finds himself being drawn into matters. Avery’s father is working on a lifetime study of Italian art and is not that pleased to see him. Enter Mrs Mountpatrick, a friend of Avery’s mother, along with another youth who is helping his father. Very soon, a delightfully entangled and complex situation develops, only to be exacerbated by the arrival of Avery’s mother, a dominatrix who uses sex-appeal and a natural upper class manner to exert her will. The tale is told by Bannerman as narrator and is full of suspense to delight the reader right up to the unexpected end.