From the publishers website:
Another of the One Night Stand Series, Jungle Ruins of Madaro-Shanti is an adventure for a party of 4-8 characters of fourth through seventh level. A century ago or more, when the town of Cholagadi was just a frontier fort on the coast, Madaro-Shanti was the most powerful city-state in the entire Ambicuaria Jungle. Its citizens were highly advanced in the arts of magic, and even retained some vestiges of magical quasi-technologies perhaps more ancient than humankind itself. Their prosperity made for jealous enemies, none more covetous than the powerful and sorcerous Kiengaa Tribe of the deep jungles. The Kiengaa plotted against Madaro-Shanti, making dark pacts with the monstrous ape-centaurs known as the Borsin, and with the monkey-faced, snake-like monsters known as the Hanu-Naga. Once this terrible, unnatural army was gathered, the Kiengaa and their allies laid siege to Madaro-Shanti itself.
As the walls of Madaro-Shanti fell, and the invaders swarmed into the city, the high priest of the city closed himself within the royal shrine, praying to all the gods for intervention. Yet none of the gods answered his prayers until the last – and that was Ojala, whom the people of Madaro-Shanti knew as a god of evil and treachery. A deadly bargain was struck that night, and true to his promise, Ojala caused a horrible wasting disease to strike the besieging army. But the full extent of the evil god’s treachery became clear when the surviving people of Madaro-Shanti themselves began to succumb to the same disease which had slain their enemies. Within a fortnight, all the people of Madaro-Shanti had either died of the plague or scattered into the depths of the predator-filled jungle.
In only a few years, the city was overgrown by the jungle and fell into ruin, but the magical disease was to have one final consequence. Not only did the contagion affect the Kiengaa and the Madaro-Shanti – it also infected the mind of a powerful nature-spirit that inhabited the surrounding jungles. The nature-spirit Cho-Odaa, driven mad by the disease and hungry for vengeance against all humankind, has discovered the means to exact a terrible reckoning.