London, March 1937: an engraved card summons the Belgian Detective and his loyal companion to Harrow Hall in Mayfair — the marble palace of a wealthy collector who made his fortune in the City and spent it on old masters, silver, and social consequence — where the card adds in a bold hand "a matter of some delicacy requires your attention, say nothing to the other guests"; around the glittering table sit a nervous rival collector humiliated once too often, a sharp-eyed journalist whose dead brother left behind a ledger of stolen-art transactions, a son drowning in debt and resentment, a fragile society woman whose hands will not stop shaking, and a cold-eyed business associate who does not flinch when his host falls face-first into the chocolate mousse; a spoon has been quietly exchanged, a smudge appears on the rim of a dish, a black kid glove is found behind the conservatory ferns with a dark stain across its fingertips, and in the dead man's breast pocket lies a note in his own hand reading "one of you has presumed too far upon my silence — that silence ends before midnight"; Part One of a two-part original Golden Age–style mystery about art, poison, and the discovery that a man who collects enemies as eagerly as he collects paintings will eventually acquire the one who kills him.