I must hurry." So she hastened up the aisle to the door, which was shut, although she had not remembered closing it after her.
She turned the knob, still smiling to herself, but the door stuck fast.

It was locked! Grace was so stunned that for a moment she hardly comprehended what had happened.

She sat down and tried to collect her thoughts.

Locked up in an upper classroom on the afternoon of the great game! She tried the one other door in the room.

It also was locked.