But I don't see what kind of a challenge an empty cage would be.

"Does an empty cage mean something to one of us?"

They hauled the empty cage off, then crossed on over.

Monk's going to have an empty cage in another two days' time.

The door of the sixth was open into an empty cage.

Will's father crouched and squinted out from around an empty cage.

Harry walked across the dark room, past Hedwig's large, empty cage, to the open window.

I'll keep it there until I have an empty cage in the breeding area.

When the king came home, he observed the empty cage, and asked the queen how that had happened.

As they passed the now empty cage at the edge of the square, Ash put his mouth close to her ear.