Sherlock Holmes and the Black Widower

In the year 1908 Holmes believed himself to be in retirement. Watson was once again in private practice and unwed. Mrs. Hudson had gone to Sussex to act as Holmes's housekeeper. But the fates had agreed that Martha Hudson and John Watson should be together. Or had they? When Dr. Watson proposes to Martha Hudson it sets off a series of events that only Sherlock Holmes can deal with. Watson has already had three wives, all have died under unfortunate circumstances. Colm Campbell, Martha Hudson's nephew, thinks there is more here than meets the eye. Is Watson just unlucky or are the deaths suspicious? Holmes must come to his best friends defence.