Helen stood on tip-toe.

“It’s Margaret,” she cried. “Something’s wrong. It looks like she’s asleep.”

But sleep in a water-logged rowboat in the middle of Lake Dubar was out of the question and Helen realized instantly that something unusual had happened to Margaret, something which would explain the whole joke which had turned out to be such a ghastly nightmare.

Jim Preston eased the Liberty alongside the rowboat and Mr. Linder reached down and picked Margaret up. There was a dark bruise over her left eye and her clothes were soaked.

The boatman found an old blanket in one of the lockers and they wrapped Margaret in it and pillowed her head in Helen’s lap.

Margaret’s eyes were closed tightly but she was breathing slowly and her pulse was irregular.

“Hurry,” Helen whispered to Jim Preston. “Head for Linder’s. Her father will be there by this time.”

The boatman sensed the alarm in Helen’s words and he jerked open the throttle of the Liberty and sent the boat racing through the night. In less than five minutes they were slowing down for the pier. The lights of a car were at the shore end of the landing and someone with an electric torch was awaiting their arrival. It was Doctor Stevens, pacing along the planks of the landing stage.

“Have you found Margaret?” he cried as the Liberty sidled up to the pier.

“Got her right here,” replied Jim Preston, “but she’s got a bad bump on her head.”