Su Yao, a 21-year-old poor student in society, has been dependent on her grandmother since she was a child. Following her grandmother's dying instructions, "Never activate the system," she refused to bind to the doomsday survival system after the doomsday warning appeared. She used the three million left by her grandmother to build a hidden underground fortress, hoard supplies crazily, and became the only human being who had not activated the system. She is cautious and tenacious, becoming the "last human being" in the apocalypse, and is targeted by a zombie bounty of 7 billion points. Finally, after accidentally learning the truth that the world has fallen into a restart loop, the reverse binding system of the key necklace left by her grandmother became the only hope to break the loop.
