Cape Colony is proving a tiresome assignment for Captain Kydd's daring commander-in-chief Commodore Popham. Rumours that South America's Spanish colonies are in a ferment of popular unrest and of a treasure hoard of silver spur him to assemble a makeshift invasion fleet and launch a bold attack on the capital of the Viceroyalty of the River Plate, Buenos Aires. Navigating the treacherous bars and mud flats of the river, the British invasion force lands and wins a battle against improbable odds,