Topological insulators (TIs) are among the hottest topics in condensed matter physics today. They're a bit strange: Their surfaces conduct electricity, yet their interiors do not, instead acting as insulators. Physicists consider TIs the materials of the future because they host fascinating new quantum phases of matter and have promising technological applications in electronics and quantum computing. Scientists are just now beginning to uncover connections between TIs and magnetism that could unlock new uses for these exotic materials.