Home Sweet Home (2005)

A family moves to a new flat on a big building. They get to know the building was erected over a burnt slum, when lots of poor people died in a non accidental fire set by the constructors. Soon their only child, a boy, is kidnapped by what seems to be a strange humanoid creature lurking in secret through the ventilation and trash pipes that connect everywhere around. As the father is heavily wounded by the creature and goes to hospital, the mother undertakes the investigation the police should do. But what she will discover will put herself in conflict with her own beliefs as a mother.