Every object in the Solar System has a unique story to tell. The fastest planet and the smallest, Mercury, appears relatively gray and dull. But it orbits relatively close to the Sun, whose powerful gravity has long pulled in stray bodies from the surrounding space, accelerating them and consuming them. Some strays never reached the Sun; Mercury got in the way. So, the little planet has experienced plenty of bombardment, perhaps not so much now as in the past, say 4 billion years ago. If cosmic collisions and consequent craters are your thing, then you’ll find nothing dull about Mercury. Mercury has interesting things to tell us, too, about planetary tilt, large or small, about elliptical orbits, and about inner structure. If you find the story of modern science full of fascination, then you’ll appreciate Mercury’s subtle role in backing up Einstein’s revolutionary understanding of gravity and space.