Aaron Thier is the author of the novel The Ghost Apple, a semifinalist for the 2015 Thurber Prize for American Humor. He writes a column, Food & Consequences, for Lucky Peach and he is a regular book critic for the Nation. His newest novel is Mr. Eternity (Bloomsbury).  Key West, 2016. Sea levels are rising, coral reefs are dying. In short, everything is going to hell. It’s here that two young filmmakers find something to believe in: an old sailor who calls himself Daniel Defoe and claims to be five hundred and sixty years old. An ingenious, hilarious, and genre-bending page-turner, Mr. Eternity is multiple novels in one. Together they form an uncommon work — about our changing planet and its remarkable continuities.