Like a lot of people, I was saddened to hear of Terry Pratchett’s death Thursday. He was a constant presence in our house for years, thanks mainly to our son’s love of the Discworld series. I’m pretty sure he read every one of them. Last year, Thomas turned us on to a non-Discworld book, “Nation,” a wonderful tale of struggle and survival after a tsunami hits a Pacific island. Or at least, a type of Pacific island: the setting is a slightly alternative universe which feels like the late nineteenth or early twentieth century but with subtle differences, such as a “Russian flu” wiping out hordes of English royalty in line for the throne. It’s what my late father-in-law would have dubbed, simply, “A good read.” Here’s a passage I noted in my book journal after devouring it just a few days: “Of course it’s a trick. Building a canoe is a trick. Throwing a spear is a trick. Life is a trick, and you get once chance to learn it.” Pratchett’s final book,”The Shepherd’s Crown,” was completed last year and is scheduled for publication later this year.