Robert J. Harris’ A Study in Crimson was inspired by the Basil Rathbone Sherlock Holmes movies. It moves the famous detective from Victorian England to World War II-era England. The time shift of Holmes, Watson, et al. provides a nice shift in perspective and setting. 
Holmes and Watson were both involved in The Great War, and that experience shaped their youth and their lives. Watson is more or less the competent and curious doctor he always is, just older. He is more upbeat than a lot of his medical peers, who find themselves either hopeless or stoic from the casualties they see daily. Holmes that bastion of rationality and logic, is twice disillusioned – first by the Great War, and now again. How the world continues to crater itself is a mystery even he cannot solve. While not exactly patriotic, he does find himself more aware of the times and his need to try and serve where he can.
The Dynamic Duo find themselves enlisted by a much-mellowed Lestrade to help solve a series of Jack the Ripper-like murders occurring in wartime London. The gang is trying to help the populace “keep calm and carry on” and avoid morale and safety dropping lower than they need to be.
The Jack the Ripper copycat killer sends communiques to journalists and/or law enforcement, and for reasons unknown will only work with a brassy American reporter. Sort of a femme fatale-type reporter, all sassy and beautiful with uncertain motives. Holmes, Watson, the reporter, and a Bond-like spy all work together to try and figure out what’s going on, before more women fall victim to the killer and panic ensues.
