Ostinato destino

Carolina Rambaldi, a rich widow, has three children: Marcello, an incurable layabout; Lucrezia, a sterile TV presenter and Cesare, a homosexual writer. She dies and, in her will, leaves the entire family's estate to the first child who will be married and have a child within a year. Then Lucrezia and Cesare hire Marina, a dangerous serial killer, to kill Marcello, but when Marina's twin sister also arrives, things get out of hand.