Here is the "deeply scary" (BBC Focus) new novel from a national best-selling and critically acclaimed author. Four hostages are rescued from a group of religious extremists in Barcelona. After five years of being held captive together, they make a vow to always watch out for one another. But they never expected this.... - The world they have returned to has been transformed by water - and the water is rising. As it continues to flow from the earth's mantle, entire countries disappear. High ground becomes a precious commodity. And finally, the dreadful truth is revealed: before 50 years have passed, there will be nowhere left to run.