In a world submerged by rising seas, can the secrets of the past be discovered? The breathtaking Sunday Times bestseller. 'Full of wisdom and heart. I loved it' Elif Shafak'A gripping page-turner' Observer'It gave me so much pleasure' New York Times2014: A great poem is read aloud and never heard again. For generations, people speculate about its message. 2119: With the UK's lowlands submerged by rising seas, those who survive are haunted by all that has been lost. Tom Metcalfe, a university scholar, pores over the archives of the early twenty-first century. When he stumbles across a clue that may lead to the lost poem, he reveals a story of entangled love and a brutal crime that challenges everything he thought he knew about the past. 'What We Can Know may well have created a new genre' Sunday Times'Brilliantly plotted... In What We Can Know, the past is an irresistible riddle' Washington Post'Propulsive... entertaining and enjoyable' Financial Times'A dazzling novel' Independent'Haunting, playful and ultimately hopeful... A wonderful book' Kaliane Bradley'A poignant love letter to the vanishing past' Guardian*A BOOK OF THE YEAR for the Sunday Times, Guardian, New York Times, New Statesman, Spectator, New Yorker, i Paper and Barack Obama*