| Percy Trevelyan, MD |
|Behind the scenes|
|Appearances||"The Resident Patient"|
Dr Trevelyan comes to Holmes to get his advice on some recent unusual circumstances. Trevelyan, a poor young doctor, has recently been set up in practice by a man named Blessington, who has agreed to pay the expenses of his practice in exchange for three-quarters of his earnings. Blessington also lives on the premises, explaining that as he has a heart condition, he prefers to have a doctor nearby. Trevelyan has also recently aquired a new patient, an aging Russian nobleman with a cataleptic nervous condition. The old man always visits the clinic with his son, who insists on waiting in the hall. However, Blessington has been upset to find that someone has been in his room while he was out. Holmes and Watson agree to accompany Dr Trevelyan to his practice. When they arrive, they are accosted by Blessington with a pistol, who later apologizes and explains he believed they were thieves. As Holmes believes Blessington to be lying to him, he leaves soon afterwards.
The following day, Trevelyan summons Holmes in a panic after learning that Blessington has apparently committed suicide during the night. After investigating the room, Holmes explains to Trevelyan that Blessington was murdered, likely by Trevelyan's patients with the help of a confederate whom Trevelyan had hired as a page. The older man had faked the symptoms to keep Trevelyan occupied, while the younger searched Blessington's room. When the men are caught, it is revealed that the men were members of an gang of robbers, and that Blessington, whose real name was Sutton, had turned informer against the gang. He had attempted to hide his identity, but the rest of the gang had found him living with Trevelyan.
Appearances in other media
Dr Trevelyan appears in a cameo role in this novel by Anthony Horowitz. Having experienced a professional decline since the Blessington incident, Trevelyan taken up a post as doctor at Holloway Prison. When Holmes is framed for the murder of Sally Dixon by Inspector Harriman, he is imprisoned in Holloway. Thanks to Dr Trevelyan's assistance, Holmes is able to distract the guards and Harriman and escape to prove his innocence.