1923. A city snakes beneath the soil of Mexicali. In it, Pi Ying, an elderly Chinese opium and alcohol trafficker, has protected for years a mystery that has accompanied him since his escape from Shang Hai, when he was just a child. The secret kept in the border town brings together a series of peculiar characters: an ambitious hunter of exotic animals obsessed with the trail of a marvelous beast, a widowed veterinarian and his son who travel the roads selling miraculous tonics while fleeing the Revolution. and his memories, and a spy for Kaiser Wilhelm II who fails in his attempt to contact Pancho Villa to propose a military alliance with Germany.

Hunters of Sudanese elephants and unusual fauna, fossil collectors in the old west and characters like the circus entrepreneur P.T. Barnum, wildlife trafficker Carl Hagenbeck and President Abelardo L. Rodríguez parade through the pages of this story that begins on the shores of Lake Bangweulu, in the Congo, and ends catastrophically in northern Mexico.