London, 1889. When Mrs. Viola Marston brings three seemingly ordinary photographs to 221B Baker Street, she presents Sherlock Holmes with a case like no other. In each portrait—taken weeks apart, in different rooms, by a reputable studio—a veiled woman in mourning dress stands at the edge of the frame. No one present recalls seeing her. No one can explain how she appeared on the glass plates. And when Mrs. Marston’s brother, Felix Dane, recognises the spectral figure and whispers a name he has not spoken in years, he vanishes into the London fog.
A richly atmospheric mystery of photographic illusion, Victorian social injustice, and the riddle that only the great detective can solve—not with logic alone, but with something rarer still: moral reckoning.
