“Come on,” said Jack. “Might as well take it all in.”

As he spoke the doors of the big shed swung slowly open. The boys saw a man pushing the portals, but something else they saw attracted their attention, and held them spellbound.

For the “something” was a great bird-like creature in the shed, a creature with an immense spread of wings, and from the big structure there came a peculiar throbbing noise, such as that they had heard in the air over their camp several nights.

“There it is!” exclaimed Nat. “There’s the monster that’s been flying in the air over our heads! They’ve got it captive, and they’re trying to tame it!”

The doors opened wider, the man pushing them with his back to the boys, so that at first he did not see them.

“Wow! Aunt Jerusha’s Johnnie cake!” exclaimed Nat. “See that bird.”

Inside the shed the great creature appeared to be fluttering its wings.

The boys were peering forward eagerly. Suddenly there sounded a shout, and from one of the cabins a figure ran.

“Jerry Chowden!” cried Jack.

Jerry had seen the boys. Pointing one hand at them, he yelled something to the man opening the shed doors. In an instant the man turned, went back into the shed, and the doors swung shut. Then, from other cabins came several men, running toward Jack and his chums. Jerry joined them.