England's Secret Weapon examines the way Hollywood used Sherlock Holmes in a series of fourteen films that spanned the years of World War II in Europe, from The Hound of the Baskervilles in 1939 to Dressed to Kill in 1946. Basil Rathbone's portrayal of Holmes has influenced every actor who has subsequently played this popular character on film, TV, stage and radio, yet the film series has, until now, been neglected in terms of detailed critical analysis.

The book looks at the films themselves in combination with their historical context. Though the first two films were set in the detective's 'true' Victorian period, Holmes was then 'updated' and recruited to fight the Nazis. He came to represent the acceptable face of England for the Americans - the one man who could be relied upon to ensure an Allied victory. Enthusiasm for a Nazi-fighting Holmes soon waned, and the series moved first into ghost-and-ghouls chillers, and finally into visceral horror films in which Professor Moriarty, Holmes' old enemy, had been replaced by a new breed of villain - a deadly female.

England's Secret Weapon analyses the way the studio steered a careful course between modernising the detective and making sure he was still recognisable as the 'old Holmes' - in clothes, locations and behaviour.