- Mary Sutherland – Holmes's client, a typist and the victim of a scheme to keep her unmarried.
- Mrs. Windibank – Sutherland's mother and co-conspirator with Mr. Windibank.
- Mr. Windibank (alias Hosmer Angel) – Wine importer and Sutherland's stepfather, who poses as Hosmer Angel to snare his stepdaughter's affections.
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