Nate reviews The Mission and is joined once again by its author, David W. Brown - a science journalist who has written for The New York Times, The Wall Street Journal, The New Yorker, Scientific American, Vox, and Smithsonian. In Part 2 of the conversation, David reveals the writing process behind his new book, makes the case for getting excited about Europa (one of Jupiter's icy moons) and considers the ethics of eating alien fish.