When Sam Elling creates an algorithm to pair people with their soul mates online, he meets Meredith, his own perfect match. But when Meredith’s grandmother Livvie dies unexpectedly, Sam puts his algorithm to even better use: it compiles Livvie’s old emails and video chats to create a computer simulation so that Meredith can say goodbye. It’s not supernatural; it’s computer science, and Meredith loves it—too much to keep to herself. Together, she and Sam open RePose to help others who have lost a loved one. Business takes off, but for every person who just wants to say goodbye, there’s someone else who can’t let go. This twenty-first-century love story asks what would happen if saying goodbye were just the beginning, and shows how love can take on a life of its own.