The Dark Energy Survey aims to make the most precise test yet of our cosmological model, dark energy, dark matter, and our laws of gravity. The four main probes we use are baryon acoustic oscillations, weak lensing, galaxy clusters, and type Ia supernovae. We have just finished the fourth year of a five-year, 525 night observing program and have already discovered thousands of supernovae, are monitoring almost 800 active galaxies, and by next year expect to have mapped approximately 300 million galaxies. The wealth of data DES produces can do a lot more than just dark energy. Using reverberation mapping we’re aiming to measure how supermassive black holes have evolved over the last 12 billion years; using microlensing we’re looking for massive black holes in our galaxy; using the 3 square degree field and 570 Mega-pixels of the Dark Energy Camera we are following up gravitational wave discoveries; and similarly watching for Kuiper belt objects and potentially planet nine. This talk will give an overview of DES and highlight the role of our 100 night spectroscopic follow-up program, OzDES, that we are running at the Anglo-Australian Telescope.