On a rainy night, delivery boy Lin Mo took a shortcut to deliver food and stumbled upon a murder in an alley. The dying old man put a blood-stained bronze ring into his hand, said angrily, "Don't let anyone see it," and then died. Lin Mo did not dare to call the police because the pursuer was nearby. He hid the ring and continued to deliver food. When he got home, he discovered that the ring was sucking his blood. Early the next morning, he found that he could clearly see the patterns of fly wings thirty meters away, and punched the wall, causing the brick to crack.
