''Cusp'', this new collection from Graham Mort, features many of the qualities readers have come to admire; keen observation, a feeling for the natural world that echoes and enhances the human interactions in his poems, the sense of the individual as part of a larger society of which we are implicitly responsible. New here is a different sort of line, which alternates short and longer lines in a step-like formation, a terracing which propels the narratives along. Also included is the remarkable, ambitious long poem, ''Electricity'', fizzing with riffs on its theme. Morts formal rigour, instinctive compassion, and warm humanity shine through in this new book, the first since his acclaimed Visibility: New and Selected Poems.