“I’d swim and get a boat, if the water wasn’t so cold,” said Tom.

“Don’t try, Tom. You’d get a cramp,” begged Zu-zu.

The boys shouted, and Zu-zu screamed, and all waved their handkerchiefs, while Bob raised his head in astonishment. Presently Tom panted:

“Somebody’s putting out in a boat, all right enough. Keep it up.”

From the mainland opposite, where lights were beginning to twinkle, a boat, barely seen against the dark shore-line, was starting out into the slough. They heard the rattle of the oars dropping into the oar-locks.

“Keep yelling,” gasped Ned.

And they did, until it was plain that the boat was making for them.

“It’s the Black Swan!” whispered Zu-zu, excitedly, as the craft neared.

“Oh, no,” scoffed Tom.

“But it is, it is!” insisted Zu-zu. “I know it is!”