A gust of wind fanned her cheek and something clicked.
The door had blown shut!
CHAPTER XXI
DRAMATICS
There are pleasanter places to be at midnight than the dark room of a strange water tower, but Betty was not frightened. She tripped over some tool as she felt for the door and discovered that she had lost her sense of direction completely.
"I'm all turned around," was the way she expressed it. "I must start and go around the sides, feeling till I come to the door."
Following this plan, she did come to the door and confidently turned the knob. The door stuck and she rattled the knob sharply. Then the explanation dawned on her.
The door was locked!
Could it have a spring lock? she wondered. Then she remembered a day when, on exploration bent, a group of girls had made the trip to the roof and the kindly Dave McGuire had taken a key from his pocket and unlocked the door of the little room for the more adventurous ones who wanted to climb up and see the inside.
"It was a flat key, like a latch key," Betty reflected. "The girls must have had the door unlocked for me to-night, but I don't think they would follow me and lock it. That would be mean!"