💍 Mary Morstan
The governess who brings Holmes six pearls and a ten-year mystery — and walks out engaged to Watson. Calm under revelations that would flatten most clients, she is the canon's model of quiet courage.
“I think that there is something amiss with Mr Thaddeus Sholto.”
The client who changed the saga
Mary Morstan comes to Baker Street with the canon's most elegant case-opening: a father who vanished ten years ago, a pearl posted to her annually by an unknown hand for six years, and now a summons from the sender. She lays it out with a composure that impresses even Holmes — and completely undoes his flatmate. By the case's end she has lost a fortune and gained a husband.
Courage of the quiet kind
Watson's narration keeps noting what Mary does not do: she does not faint, does not weep, does not press questions for which there are no answers yet. Rowed across a midnight Thames toward a treasure and a murderer, her chief concern is for the frightened housekeeper left behind. The canon admires nerve in many forms; hers is the kind that steadies other people.
The treasure and the toll
The Agra treasure would have made Mary the richest woman in England, and both she and Watson understand it would have stood between them like a wall. When the iron box proves empty, Watson thanks God — and the reader is meant to agree. Her marriage removes her from the stories almost entirely, but her case remains the canon's best argument that the client matters more than the loot.