A graphic novel in the series ‘Corto Maltese’. East Africa, 1918, in the Rufiji Delta Lieutenant Tenton and Captain Mac Griogair of the British Army, welcome Corto on board the Königsberg, a German battle cruiser put out of action by the English. Here, Corto comes across a band of the Leopard-Men - a secretive police force who enforce the native law of Africa - and is dragged by into a tale of secret treasure and old questions of honour and vengeance.