Seven years ago, an ordinary graduation party was recorded on a 47-minute video. There were only eight people in it from beginning to end. Yet years later, a group photo from that night clearly showed nine people. Stranger still, the ninth person in the photo disappeared the day after the party, while the eight others all denied that he had ever been there.
Image analyst Cheng Yan is commissioned to reinvestigate the case. As the old video, photos, ride-hailing records, chat logs, and witness statements from that year are brought to light again, he discovers that none of the eight seems to be telling the whole truth.
Then he notices a question everyone else has overlooked:
If there were nine people in the photo, who pressed the shutter?
Perhaps there were always more than nine people in that room seven years ago.
