Poetry, Michael Harlow writes, is when words sing. In The Tram Conductor's Blue Cap, his remarkable new collection, words do sing; they also shout and whisper, riddle and recur, express and evade. Though these poems are often allegorical and philosophical, the real underlies the imagined (while the imagination invents the real), so we meet a stranger in the Oyster Bar at the Grand Central', we travel to Athens and Mexico and Troy, we hear from Sappho, Marco Polo, Cavafy and Emily Dickinson. And at the centre of the collection is a tram conductor, 'inside a story that dreams / him'. As a habit of imagination, these poems circle and cultivate patience, anticipation, memory, opportunity, delight and regret. Fans of Harlow's previous, accomplished collection, Cassandra's Daughter, will be thrilled to find this poet in assured voice: building up 'one word one word and then / another, waiting for the light to come / stealing in'.