Why is the lamp still off?

It is the end of the day.

Clara sits down with her book.

The room gets dark.

Clara presses the switch.

But the lamp stays off.

She presses it again. Still nothing.

Clara follows the cable with her eyes.

The lamp is unplugged!

Here is the socket.

Clara picks up the plug.

She plugs in the lamp.

Clara switches on the lamp.

The light shines on the book.

The room is bright.

Clara reads quietly.

Later, Clara closes her book.

Clara switches off the lamp.

Clara leaves the room.