Libbie handed her slip of paper to Betty without a word.

“Go to bed at once,” the latter read aloud.

There was a gale of laughter.  Libbie, the curious, who dearly loved to hear and see, to be sent off to bed in the middle of the most wildly exciting night they had known in weeks!

“Hurry,” admonished Bobby.  “You’re disobeying by staying up this long.  Where’s your character, Libbie?”

Libbie scowled, but departed, grumbling that she didn’t see why she couldn’t stay up and watch Norma walk down in the cellar.

“Mine is the most spooky,” said Betty, when the door had closed behind Libbie.  “Listen—­I’m to climb the water tower at midnight and leave this card there to show I have complied.”

She held out a little plain white card in a green envelope.

“Hark! was that somebody at the door?” asked Bobby, and she ran over to it lightly and jerked it open.

The corridor was empty.

“We’re all nervous,” remarked Betty lightly.  “I’ll set the alarm for eleven-forty-five and put the clock under my pillow so Miss Lacey won’t hear it.  I’ll lie down all dressed, and then I won’t have to use a light.  She might see that through the transom.”

“Don’t you want some of us to go with you?” asked Constance.  “We needn’t go up into the tower, if you say not.  But at least we could go that far with you; you might fall off the roof.”

“No, please, I’d rather go alone,” said Betty firmly.  “It’s a test, you see, and the idea isn’t to make it easy.  I’ll be all right, and in the morning the girls will find the card and know I didn’t flunk.”

After the girls had gone away to their own rooms the clock was set for a quarter of twelve, but Betty and Bobby decided that they might as well stay awake till midnight.  They would lie down on their beds—­Betty insisted that Bobby should undress and go to bed “right”—­and wait for the time to come.  Within twenty minutes they were both sound asleep.

The muffled whir of her alarm clock awakened Betty.  For a moment she was dazed, then recollection cleared her mind.  She slipped to the floor without waking Bobby and softly tiptoed from the room.

A dim light burned in the corridor, and Betty knew the way to the water tower.  To reach it, one had to mount to the roof of the dormitory building.  Betty experienced a little difficulty with the obstinate catch of the scuttle cover, but she finally mastered it and stepped out on the tarred graveled roof.  The water tower, a huge tank on an iron framework, had a little enclosed room built directly under it reached by an iron ladder.  Here the engineer kept various plumbing tools.  It was in this room that Betty was to leave the card.

The night wind blew damp and keen, and the stars overhead seemed very far away.  Betty had no sense of fear as she began to climb, mounting slowly and feeling for each step with her hands.  The friendly dark shut in around her and somewhere in the distance a train whistle tooted shrilly.