It is 1916 and Sherlock Holmes has returned to his rooms in Baker Street after attending the funeral of his long time associate, Dr John H Watson. Holmes reflects on the old days and comes to realise that not only was there so much that he had shared with Watson in his lifetime but also there was so much that he had not revealed to him: things he had kept hidden, including his deep affection for his friend. As Holmes delves deeper into the darker aspects of his own history, he reveals a shocking secret. Realising now how lonely and isolated he is without his old comrade, and adrift in a new modern and war-ravaged age, he comes to wonder whether, like Watson, he too has come to the end of his time...