A decades-old cosmic mystery has finally been cracked: the strange X-rays coming from the bright star gamma-Cas are caused by a hidden stellar companion feeding off it. Using cutting-edge observations from the XRISM space mission, astronomers discovered that an unseen white dwarf star is siphoning material from gamma-Cas, heating it to extreme temperatures and producing powerful X-ray emissions. This breakthrough resolves a puzzle that has baffled scientists since the 1970s and sheds new light on how these unusual stellar pairs form and evolve.