Hollis is a retired soap manufacturer, richer than Croesus and some say mad. Obsessed with amassing precious stones and bullion, Hollis chooses a strong room to deposit his dazzling hoard. But when he discovers that he's the victim of an elaborate and enigmatic robbery, even though the room was never broken into, Dr Thorndyke is summoned to bring his unrivalled knowledge to bear on a remarkable mystery.The tropic moon shone brightly on the village of Adaffia in the Bight of Benin as a fishing-canoe steered warily through the relatively quiet surf of the dry season towards the steep beach. Out in the roadstead an anchored barque stood up sharply against the moonlit sky, the yellow spark of her riding light glimmering warmly, and a white shape dimly discernible in the approaching canoe hinted of a visitor from the sea. Soon the little craft, hidden for a while in the white smother of a breaking wave, emerged triumphant and pushed her pointed nose up the beach; the occupants leaped out and, seizing her by her inturned gunwales, hauled her forthwith out of reach of the following wave."You know where to go?" the Englishman demanded, turning a grim, hatchet face towards the "headman." "Don't take me to the wrong house."The headman grinned. "Only one white man live for Adaffia. Me sabby him proper." He twisted a rag of cotton cloth into a kind of turban, clapped it on his woolly pate and, poising on top a battered cabin-trunk, strode off easily across the waste of blown sand that separated the beach from a forest of coconut palms that hid the village. The Englishman followed less easily, his shod feet sinking into the loose sand; and as he went, he peered with a stranger's curiosity along the deserted beach and into the solemn gloom beneath the palms, whence came the rhythmical clamour of drums and the sound of many voices join ing in a strange, monotonous chant.Through the ghostly colonnade of palm trunks, out into the narrow, tortuous alleys that served for streets, between rows of mud-built hovels roofed with unkempt grass thatch, where all was inky blackness in the shadow and silvery grey in the light, the stranger followed his guide; and ever the noise of the drums and the melancholy chant drew nearer. Suddenly the two men emerged from an alley into a large open space and in an instant passed from the stillness of the empty streets into a scene of the strangest bustle and uproar. In the middle of the space was a group of men, seated on low stools, who held between their knees drums of various sizes, which they were beating noisily, though by no means unskilfully, some with crooked sticks, others with the flat of the hand. Around the musicians a circle of dancers moved in an endless procession, the men and the women forming separate groups; and while the former danced furiously, writhing with starting muscles and streaming skins, in gestures grotesque and obscene, the latter undulated languorously with half-closed eyes and rhythmically moving arms.The Englishman had halted in the black shadow to look on at this singular scene and to listen to the strange chant that rang out at intervals from dancers and spectators alike, when his guide touched him on the arm and pointed."Look, Mastah!" said he; "dem white man live. You look um?"The stranger looked over the heads of the dancers, and, sure enough, in the very midst of the revellers, he espied a fellow-countryman seated on a green-painted gin-case, the sides of which he was pounding with his fists in unsuccessful emulation of the drummers. He was not a spectacle to engender undue pride of race.