"Blue Line?" asked a man outside a pizza place, and walked me there

It was after midnight near Wicker Park and I had a dead phone and a very light jacket. A man coming out of a pizza place looked at me and said, Blue Line? He walked three blocks with me in the cold, pointed at the stairs, and went back to his friends. I got home with feeling in my toes and a small lesson about how to talk to people in the dark. I do not have his name. I have a slice of pizza that I bought the next day, in his honour, at the same place.