Following Equal and Opposite Reactions and Hail Mary, Tropical Depression is the final chapter of a poignant comedy cultured in the petri dish of human relationships.

After being deported from the United States, Lupe and Ascensión Guzman have returned to Krukrulitos, their Nicaraguan jungle village at the foot of the giant volcano Momotombo, upon whose slope a vast geothermal plant has been built to power the tropical metropolis of León.

Lupe and Ascensión struggle to readjust to life with Ascensión's large, overbearing, over-opinionated extended family whom they must support with their jobs at the Momotombo plant. They grieve privately for the American-born child they left behind and Lupe suffers from debilitating depression that makes her the object of derision among Ascensión's relatives.

But the young couple finds an unexpected friend and ally in the chief hydraulic research officer of Momotombo, an expatriate American woman with long-simmering family issues of her own that have made her into a knowledgeable veteran of emotional volcanoes and jungles of the heart.