C212 Strange Case to Find the Real Culprit(6)

If they couldn't find a way to lock the door from the inside, then there was only one possibility, and that was that someone locked the door from the outside. In that case, there should be another person besides the five dead people and Kin Mingda, who was drunk and never woke up, when the event happened.

Then, who was this person?

Moreover, Lu Qingwan had asked the driver before