Under the assumed name of Stapleton, Roger of Baskerville is condemned to death for being instrumental in the death of a relative and probable heir to the Baskerville estates. After his plea of clemency is denied, he overpowers his keeper and escapes, taking up his residence near Baskerville Castle, and announcing himself to Lord and Lady Baskerville as Loris Collamore, a new neighbor. The next day he succeeds in inveigling them into a submersible house which he has built in a nearby lake, and making them prisoners. He then goes to the castle and announces to the servants that he is a relative of Lord Henry and has come to take charge of his affairs. The servants become suspicious of the intruder, and being mystified at the strange disappearance of their master and mistress, seek the aid of Sherlock Holmes, who had been mainly instrumental in securing the conviction of Roger.