Night Laundromat, the Number in the Coin Box

At two in the morning, night attendant Oh Jung-han was found unconscious inside a 24-hour unstaffed laundromat with a severe head injury. The coin box bolted to the wall had been torn open and emptied. Between 01:00 and 05:00 the laundromat runs in night-lock mode: the door will not open, in either direction, without a member card. The victim cannot speak, and the police have told no one how much was taken. Yet one of the four people questioned said a number that has never appeared anywhere in the world.