Then her eye rested for a second on the little key that hung on her watch chain.

It was the key to the lean-to in which David kept his aeroplane.

Like a flash the way was revealed to her.

But would she be able to carry out the daring design that had sprung into her mind?
She would try, at any rate.

With an unconcern that she was far from feeling, Grace walked carelessly toward the door of the lean-to.
The demented man was beside her in a twinkling He clutched Grace by the arm with a force that made her catch her breath.
"What are you trying to do!" he exclaimed, glaring at her savagely.
"Didn't I tell you that you couldn't go away!" He held her at arm's length with one hand, and threateningly shook his finger at her.
"Remember, once and for all, that I am your emperor and must be obeyed.
Disregard my commands and you shall pay the penalty with your life.