Astronomers are searching for intermediate-mass black holes, in between the stellar and supermassive varieties. Recently, a group of researchers announced the discovery of a high-velocity star rocketing out of the globular cluster M15, ejected about 20 million years ago and hurtling at 550 km/s on an escape trajectory from the Milky Way. The astronomers think this could have been caused by a three-body interaction with an intermediate-mass black hole.