The Last Variable in the Universe

At 4:17 in the morning, the universe went dark for seven seconds. Astronomer Gu Heng discovered that his colleague Zhou Ning was deleted from the world, the pocket watch left by his father began to move backwards, and another self was sleeping underground. Seventy-two hours later, the Creator will return to zero human civilization. In order to retrieve Zhou Ning and regain the right to choose the future of all lives, Gu Heng must become a variable that even the universe cannot predict.