In the Chilean Atacama desert, the skies seem to stretch on for infinity. They almost do: this is one of the richest areas on earth for building astronomical observatories, so dry, unpolluted, and clear is the air. Yet beneath those skies, the ground holds an together different story – the Atacama desert was one of the Pinochet’s regime’s favourite places for dumping the bodies of murdered political prisoners, and today it is scoured by the relatives and loved ones of those same victims looking for answers. Patricio Guzmán’s Nostalgia for the Light is a documentary about astronomy and about Chilean history, but it is also an intensely personal essay film, about his obsession with both subjects and their unexpected historical and philosophical similarities. Few films mix so many disparate subjects as this without becoming lethargic, nonsensical and incoherent, but Guzmán’s approach – aiming for poignancy without sacrificing intellectual rigour for emotive pleading – ensures a fantastic experience.