The Pantanal is a wild region in Brazil where the dry season alternates with the rainy one.
Zog is the elder of the howler monkeys and was ruling his clan with equanimity in the haven of a generous forest. But for obscure reasons that no one can fathom, the winds haven't blown this time. They haven't brought the usual “rivers from the sky“ with them which is a tragedy since they bring life back to the dried out forest. The rain shortfall turns upside down everything Zog always believed to be in the natural order of things. His people will have to face hunger and thirst for the very first time.
The buds have not blossomed. The water saved up in tree trunks has dried out and the swamp's king, the anaconda Olim, sneaks into the forest intent on capturing Zog who is weakened.