Infinite Puzzle: Failed Informant

My informant left the last words on the phone: "There are others on the list." Then the line went dead. I called back and got only a busy signal. At three o'clock in the morning, I rushed over to the address he said - the door was unlocked and the room was dark. The phone screen is the only source of light. Above is the message he sent me eight hours ago: "Old place, tomorrow at noon." The message appears as read. And the person reading this message is standing behind me right now.