What happens to the food we digest after it leaves our body? Is it waste that is thrown away or a resource that can be reused? In search of answers, director Rubén Abruña embarks on an investigative and entertaining search through 16 cities on four continents. He follows the trail of feces from the long sewers of Paris to a huge sewage treatment plant in Chicago.

Sihja is a young, charming and a little outrageous fairy who leaves her home in the forest. On arrival in the city, she meets a sensitive new friend, a lonely human boy Alfred. Sihja loves the newly found organized urban shapes and orderly habits that the city people have. One day dead birds appear on the city streets. Alfred and Sihja must find out what is threatening the nature.