The Baskerville Curse

Book 1 in a series of chronological stand-alone plots.
England 1899. Ten years after Holmes and Watson solve the case of the Baskerville hound, Dr Watson receives an invitation to return to Baskerville Hall. The night before his departure he meets a Ukrainian countess who claims to be the daughter of Sherlock Holmes and Irene Adler. She is vain, rich, fiercely intelligent, and she ends up accompanying him to Devon.
The same characters from the original story have re-assembled at Baskerville Hall and it appears that someone is out to destroy Sir Henry Baskerville. When the baronet drowns in the Grimpen Mire a spate of anonymous letters is believed to have induced him to kill himself.
Several further deaths follow in quick succession. Dr Watson and Countess Volodymyrovna are not sure whether the deaths are accidents, suicides or murders, and they soon find themselves out of their depth. They even question whether they are merely playing to their own vanity as the best friend and illegitimate daughter of the greatest detective who ever lived.
Book 1 serves as an introduction to the pairing of Dr Watson and Countess V, therefore I have chosen to rework a story familiar to most readers of the genre - one of Conan Doyle's most enduring works. It is the only plot to borrow from ACD. All subsequent plots are original.