A decade or two into the future, after a tumultuous global climate event called the Change, an island nation (much like England) has built a Wall to protect itself against marauding outsiders, known as the Others. Those charged with protecting the borders, known as the Defenders, must maintain a 24/7 vigilance against attack and penetration. In many ways, it’s a world not all that different from what we know today, except that—as one example—rising waters around the planet have made beaches extinct.