Paramount+ presents BEFORE I FORGET, the story of Pascual León, a retired, bitter 65-year-old, diagnosed with the beginning stages of Alzheimer's. Pascual's reaction to the diagnosis is unsuspected: he creates an elaborate infographic of people from his past and begins to murder them one by one, leaving each victim with a message addressed to a young, up-and-coming police officer, Jimena Guerra. As Pascual's memory fades, Jimena regains her own and discovers a memory from her childhood is the hidden motive behind the murders. Pascual León is an avenger who decides he will right these wrongs before he forgets.