At 221B Baker Street the smell of one of Homes' chemicals evoke memories of the 66th Regiment in Afghanistan of 1880. This is Doctor Watson story of his time in that war.
An interesting story ( )

This Sherlock Holmes spin off story depicts Watson's war time experiences as an army doctor wounded while serving in Afghanistan, before meeting the great detective. It's an interesting idea, but the realisation was unconvincing. The narrator's voice just didn't sound like Watson and Holmes's dialogue in the last chapter where Watson is recuperating in Baker Street also just didn't sound like him. Almost as bad were the simple inconsistencies between facts as given here and as given in A Study in Scarlet, e.g. the orderly who rescues him is here called Bowler, whereas he is Murray in Doyle's first story. The only positive aspect was that it offered a well drawn picture of how experiences in wartime can lead to mental health problems including depression. This is presumably based on the author's own time in the army (he appears to be the same Patrick Mercer who retired as a Colonel in 1999, is now a Tory MP and has written novels set in the current war in Afghanistan). ( )