On an ordinary afternoon in midsummer, Zhang Qiong's mobile phone suddenly received a text message from Yisuda saying that a courier had been placed in a cabinet in the community and needed to be picked up. When he looked at the courier, there was no place to send it, and the recipient's name, address and phone number were all his own. When I opened the express delivery, there was a white card wrapped in a blank envelope. I thought it was a prank, but I never thought that the moment I opened it, the wheel of fortune began to spin rapidly and the trajectory of fate began to change. Who is the sender of this express delivery and where does it come from? Everything is unknown.