A Pair of Hairbrushes

Mary: I've lost two small hairbrushes, Claire. They're a pair.

Claire: Have you looked carefully everywhere?

Mary: Yes. They're nowhere here.

Claire: Have you looked upstairs?

Mary: Yes. I've looked everywhere upstairs and downstairs. They aren't anywhere.

Claire: Hh! Are they square, Mary?

Mary: Yes. They're square hairbrushes. Have you seen them anywhere?

Claire: Well, you're wearing one of them in your hair!

Mary: Oh! Then where's the other one?

Claire: It's over there under the chair.