From the big bang and inflation to supernovae and black holes, the most violent events in the Universe are the most exciting. Streaming across space, the messengers from these cataclysmic events may yet hold the keys to unlocking the deepest secrets of nature.The next few years, driven by experimental advances, a revolution in our understanding of the cosmos can be confidently predicted. Gravitational waves will be detected, opening an entirely new window on the Universe. The next generation of dark matter searches are reaching the sensitivity at which theory predicts a signal may be seen. Very high energy gamma ray astronomy will be transformed by the building of the Cerenkov Telescope Array. Collectively and coherently, these will provide unprecedented access to the physics in the most extreme of environments. Welcome to Astroparticle Physics!