The Doctor's Case

Plot summary

Dr. Watson narrates a heretofore unreleased case in which he and Holmes are called by Inspector Lestrade on an unexpectedly rainy day to investigate the murder of the sadistic Lord Hull. Each member of Hull's family - his wife and three sons - has reason to murder him; his wife and bowlegged son suffered from constant abuse, while another son was doomed to never receive more than a pittance, due to his placement in the family line. Furthermore, Hull's family endured his treatment in the hopes that he would leave them with his considerable wealth; however, they had recently learned that Hull had rewritten his will so that none of them received a thing. Despite these motives, the family have effectively given each other alibis and the murder itself is effectively a locked room mystery; there's no place in Hull's study for anyone to hide without being seen, and all the doors and windows were locked by the lord himself.

Holmes is eager to solve this mystery, but is allergic to Hull's numerous cats. Watson, however, notices that a certain table in the locked study casts odd shadows on the rug. When he goes to check the table, he discovers an illusion and demonstrates that the table has been rigged. The bookshelf's lowest shelf is, in fact, a photorealistic painting. The murderer, Hull's artist son Jory, had perfectly rendered the bottom shelf, then pasted the results against the back table-legs. When his father announced the new will, Jory made into the study, crouched behind the table, and rushed out to stab his father at the right moment. A cursory glance would not betray the illusion on a dark day, but on a sunny one, the lack of shadows being cast by the table-legs would have been noticeable. To help make the illusion perfect, Jory had prepared shadows out of black felt, and laid them down at roughly the place where shadows should be. Unfortunately, he was "caught by shadows on a day when there should be none". Furthermore, Hull had time to scream before he died, arousing the attention of his servants and making it impossible for Jory to either collect his paintings or frame the murder as a break-in gone wrong. Instead, Jory stole and burnt the new will, guaranteeing that he and his family would receive their inheritance.

As Watson explains his insights, he slowly comes to the realization that Jory could not have executed the murder on his own and that, at the very least, everyone in the family knew of it and was lying for him. Holmes, who had already reached that conclusion while listening to Watson's narrative, gently chides him for his inability to understand the depths of human depravity. Watson also realizes that Holmes had understood everything not long from the beginning of Watson's story, yet deliberately kept his silence, letting Watson have his moment in the sun; rather than resenting his thunder being stolen, Holmes was genuinely impressed with the "deductive light" Watson demonstrated.

Holmes and Lestrade discuss the various sentences that the Hulls will receive if the case is brought before court; Jory is guaranteed an execution, whilst the other two sons would be jailed for life and the wife jailed for some time in a women's prison. They eventually decide that the world is, perhaps, better off without Hull in it, and thus conspire to conceal the truth of what has occurred; Holmes and Watson collect the painting and the shadows, while Lestrade unlocks one of the windows in the room; they leave, and inform the waiting police that Hull was murdered in an attempted break-in.