In complex fault zones, multiple seemingly disconnected faults can potentially rupture at once, increasing the chance of a large damaging earthquake. Recent earthquakes including the 1992 Landers, 1999 Hector Mine and 2019 Ridgecrest earthquakes in California, among others, ruptured in this way. But how can seismologists predict whether individual fault segments might be connected and rupture together during a seismic event?