NASA's Kepler spacecraft was designed to find exoplanets by looking for stars that dim as a planet crosses the star's face. Fortuitously, the same design makes it ideal for spotting other astronomical transients—objects that brighten or dim over time. A new search of Kepler archival data has uncovered an unusual super-outburst from a previously unknown dwarf nova. The system brightened by a factor of 1,600 over less than a day before slowly fading away.