The conversation between human and AI assistant.
How can you find out an old friend's phone number?
That's a good idea, but unfortunately I don't have any mutual friends or know any of their family members. Is there anything else I can try?
If you know where they work, you could try calling the company's main line and asking to be transferred to their department. They may not be able to give out personal information, but they can pass along a message for you.