The brilliant and disturbing work Qui a Connu Lolita? (Who Knew Lolita?), or as it is more provocatively titled in the authors' English translation Who Killed Lolita?, starts with a precis: voices tell us there have been three deaths, of a mother and her two children, the bodies found in their Marseilles apartment two months later.

This is a composition for radio, not a collection of easy evidence for a police dossier. Who did kill Lolita? Who is to blame? The program draws its power from suggestion, like footnotes plucked from a subterranean soundtrack. It poses uncomfortable questions and leaves the listener to find answers, if any there be, and to harken to voices whispering from the shadows which hint at psychological depression, at pride, at faith, hope and charity. Church bells function to create beats, and they establish the rhythm of scenes, but tellingly (tollingly?), they also suggest and judge. The pace is deliciously careful, pausing all along to invite the listener in to the program, leaving wide spaces for the imagination. The more people we hear from, the more murky the mystery becomes.

Long after hearing a powerful documentary feature, what is it you most remember about it? The atmospherics, a sound, a striking image, a provocatively posed question that can't be avoided, yet has no simple answer? Many moments in Lolita may transport you into another realm of listening, a heightened sense of wonder at the producers' skills. I'll point your attention to just two gob-smacking scenes which got under my skin, and will stay with me forever. Qui a Connu Lolita/Who Killed Lolita? is a deeply fascinating work. Listen, and you will never forget it.