Don't Tread On Me

"Hello," I said.

It was Irene, my landlord, entering the building this afternoon.

"Hello," was the response.  I held the inner door for her while she held the outer door for me.

Why was she coming in?  Was she going to check on the construction on the third floor?  What if she was going to knock on my door?  No, then she would have said something to me.