Voracious, bizarre, and bewitching, supermassive black holes are thought to haunt the mysterious hearts of perhaps every large galaxy in the observable Universe--including our own Milky Way. Our Galaxy's resident dark heart is named Sagittarius A*--Sgr A* , for short (pronounced saj-a-star), and it is dormant now, but still manages to awaken from its slumber now and then to dine on an unlucky star or cloud of gas that has wandered too close to its gravitational embrace. Sgr A *, despite its currently quiet nature, still has enough "life" left to surprise astronomers with a sudden and dramatic episode of turbulent activity. In October 2019, a team of astronomers announced that they had found evidence of a recent cataclysmic flare that exploded so far out of the Milky Way that its destructive influence was felt 200,000 light-years from its origins. This enormous, expanding beam of energy erupted close to Sgr A* only a "mere" 3.5 million years ago--which is only a...