Yves, the son of an academic couple, returns home from drug rehabilitation and struggles to find direction in his life. Charles, a friend of his father's, is an ant researcher and offers Yves a job in the university lab. Yves is tasked with maintaining the ants and their nests while documenting all the steps. After a few months, Yves becomes an ant expert, but for the former drug addict, it is a rocky road as relapses are always a threat. Then he meets Lydia, who becomes a great support for him. Suddenly, the Spanish-French border mountains are threatened by giant killer ants. Charles aims to avert the threat to the residents and eliminate the ants.