The Naval Treaty characters

Appears from the start

A consulting detective asked to recover a missing diplomatic document before its loss becomes an international crisis. Holmes separates the original theft from the later events at Percy Phelps's home and uses the sickroom itself to set a trap.

Appears from the start

Holmes's friend, doctor, and narrator. Percy Phelps knew Watson at school and appeals through him for help, bringing Watson into a case that moves between the Foreign Office and the Phelps household in Woking.

Appears from the start

A former schoolmate of Watson who has risen to a trusted post at the Foreign Office. A secret naval treaty vanishes while he is copying it after hours, and the shock leaves him with a prolonged brain fever and fear that his career is ruined.

Appears from the start

Percy Phelps's fiancée and devoted nurse during his illness. She remains in or near his sickroom for weeks, providing a constant watch over a patient who believes the missing treaty has destroyed his future.

Appears from the start

Annie's brother, whose room at the family house is given to Percy when the sick man is brought from London. His changeable finances and position within the household eventually draw Holmes's attention.

Appears from the start

Britain's foreign secretary and Percy Phelps's uncle. He entrusted Percy with the confidential treaty and explains to Holmes the diplomatic danger if its contents have reached another power.

Appears from the start

The detective conducting the official inquiry into the missing treaty. He has investigated the Foreign Office staff and the commissionaire's family without finding evidence strong enough to identify the thief.

Appears from the start

The commissionaire on duty at the Foreign Office on the night the treaty disappears. He is downstairs when Percy leaves the copying room to ask why the coffee he ordered has not arrived.

Appears from the start

The commissionaire's wife, who works as a cleaner in the government building. Her unexpected appearance and hurried journey home make her an early suspect in the disappearance of the treaty.