1917. Private Daniel Dawkins fights at Messines Ridge and Passchendaele. He writes home to his true love, Joyce, but reveals little of his extreme bravery, his kindness, his loyalty to his comrades and the horrors they experience on the Western Front. 1920. Captain Peter Harding is tasked with a secret mission to assist in the selection of a body dug up from the battlefields of Flanders to be buried in Westminster Abbey as the 'Unknown Warrior'. 2011. Sarah Harding discovers Daniel's letters and Peter's diaries. Together with historian James Marchant she pieces together the hidden truth behind the Tomb of the Unknown Warrior and must decide what to do with it.