In our small corner of the universe, we know how some matter behaves most of the time and what even less of it looks like, and we have some good guesses about where it all came from. But we really have no clue what's going on. In fact, we don't know what about 95% of the universe is made of. So what happens when a cartoonist and a physicist walk into this strange, mostly unknown universe? Jorge Cham and Daniel Whiteson gleefully explore the biggest unknowns, why these things are still mysteries, and what a lot of smart people are doing to figure out the answers (or at least ask the right questions).