In the hot summer of 2011, against the backdrop of the economic crisis and the Anti-austerity movement in Spain, Madrid is "invaded" by a million and a half of pilgrims awaiting the visit of Pope Benedict XVI. Two police inspectors are commissioned to investigate a brutal serial killer who rapes and kills older women. The two inspectors will have to solve the case in a short time and without too much clamor. The ending is unexpected and after three years from the facts told.