I received a call quite early in the day and chose not to answer, as I didn't recognise the number at all. They left a message, saying they were trying to reach someone named Nathan who was tardy for work, urging him to return their call. I had a hunch it was likely a dodgy setup, so I promptly blocked the number just to be on the safe side.

Received a call from this number, but the caller didn't bother to leave a message. Quite puzzling, really.