Fourteen-year-old Siddharta lives in Rome with his mother, Silvia - an affectionate, rambling, though shifty woman. She does not work. She lives by her wits, her friendships, her relationships. She's separated from Siddharta's father, Massimo, who does his best to help them. With Roberto she has a five-year-old daughter, Domitilla, who lives with her own father, from whom Silvia is also estranged. The two siblings love each other very much. Domitilla moves in for the Christmas holidays, and, one day while rummaging among her mother's trousse, gets hurt by a syringe. Emotional turmoil ensues. Siddharta has to live on in spite of his parents' mis-doings. He sends Domitilla to do HIV, HBV and HCV tests without their parents' knowledge. Hence, he has to use his own name. That causes unexpected trouble.