Orphaned, lonely, and lost in his photography work, Tom has no intention of falling in love. And yet, love finds him in the shape of beautiful Vanessa, who lives a dangerous double life in the heart of London's King's Cross. Tom's pursuit of Vanessa leads him to discover an alternate world, hidden amongst the streets and rooftops of London - and inhabited by strange and colourful beings. In this mysterious realm, two ancient factions - one of night, one of day - have waged war for centuries over a forbidden love and a long-lost prince of sun and starlight. But when Tom finds a secret market that appears only in moonlight, where charms and spells are bought with memories, he starts to wonder whether he's been here before.