Mayte Soldevilla (Toni Acosta) is a mother who is currently selling copies of the TurboThunder 3000, a last-gen kitchen robot, but is struggling to sell enough copies. During an AMPA reunion, she offers all of the parents in it the idea of coming over to her house to give a demonstration of the machine out of desperation, but only her three friends - Lourdes Sanguino (Malena Alterio), Virginia Torres (Nuria Herrero) and Amparo Pérez (Mamen García) - accept. They are also joined last-minute by a fifth guest, Elvira (Marta Belenguer). Things go south when the machine malfunctions and somehow causes Elvira's death. Since Elvira constantly made the other four women's lives impossible and all of them had motivations to kill her, Mayte, Lourdes, Virginia and Amparo are fearful that people (specially their loved ones) will think they killed her on purpose and, because of this, they try to hide the tragic outcome of the demonstration - which will be easier said that done and will put the four...