Manuel, an octogenarian with dementia, moves in with his son Mario and family following the sudden suicide of his wife. One evening at dinner Manuel declares that he will kill them all in their sleep.
It's the hottest summer in history, the apartment is sweltering and claustrophobic and Lena, Mario's wife, believes that something dreadful is bound to happen because of Manuel's strange behaviour. But it is not just Manuel who is acting strangely, all the old people in their building are exhibiting violent tendencies as the temperature continues to rise.