Mollicutes are a class of simple bacteria characterised by the lack of a bacterial wall and their very small genomes (500 kb to 2200 kb). Acknowledged experts critically review the most recent advances in the evolution, genetics and molecular pathogenesis of these important pathogens.

Daniel Lefebvre (Phillipe Torreton) works as the principal of an infant school in the poverty stricken region of Hernaing. His attempts to serve his pupils are thwarted by the incompetence and laziness of the local authorities. He becomes involved with the struggle of a local family to escape from the squalor and depression of the area. However, all his efforts seem in vain, and his wife Valéria (Maria Pitarresi) grows resentful of his reluctance to have another child.