Averno is a small crater lake in southern Italy, regarded by the Romans as the entrance to the underworld. That place gives its name to the Nobel Prize winner in Literature, Louise Gluck's new collection: in a landscape turned irretrievably to winter it is both passageway between worlds and an impassable barrier. The book proceeds as a sequence, an extended lamentation, its long restless poems no less spellbinding for being without conventional resolution or consolation, no less ravishing for being savage and grief-stricken.