“I never knew there was an entrance to a tunnel here!” said Tom, as he looked about him. “But then I’ve never explored here very much.”
Nor had any of the other lads of Shopton. Barn Door Island was a barren place—merely a collection of scrubby trees and tangled bushes and great boulders set down at the swampy end of Lake Carlopa. It was not a good fishing location and too dreary for picnic parties, so Barn Door was seldom visited.
“But if I had an idea there was a tunnel entrance here—the beginning of a passage that led under the lake and under the land right up to our place I’d have done a lot of exploring, that’s sure!” Tom told himself. “That’s a natural tunnel, I’m positive of it, at least most of it is. Somebody went along it until they got to the end near our fence. Then they broke out, put in those steps and made the plank covering for the opening. They put earth over the planks so no one would see them. That part must have been done recently, for we were trying airships out in that field a month ago and I landed right near that bush behind which the man disappeared. I know I did, for I remember thinking I might crash into the fence. So the land end of this queer tunnel has only been opened lately. This island end must have been here a long while. But it’s queer no one knew of it. And I wonder what it’s being used for? Something to do with our business, I’m sure. Our enemies are at work again!”
Tom quickly reviewed the situation in his mind. Since his Chest of Secrets had been taken and he had had so much trouble in recovering it, he had been very cautious about his plans of new inventions. Suspecting several of his newer employes, he had gotten rid of them and had taken great precautions, on the advice of Ned and his father.
“But if there’s a tunnel from this lonely island under the lake and beneath the shore right up almost to our plant, it means that something desperate is in the wind,” reasoned Tom. “They must have resented my blundering into it as I did, and they tried to put me out of the way. After they doped me they must have carried me a long way through the tunnel, to chain me fast near this end.
“Well, I’m free now, and out in the open. About noon, I should judge by the sun and by the way my stomach feels,” Tom went on, with a grim smile, for he was getting hungry and feeling a bit weak now. “I hope it isn’t more than the next day,” he went on, meaning the day following his night encounter with Ned.
He looked about him. Barn Door Island was about five acres in extent, large enough, on account of its wild character, to give concealment to any number of enemies. But if there were any such here now they did not show themselves as Tom eagerly and anxiously scanned the somewhat wild landscape.
“Well, now that I know where I am, though I can’t understand how or why I was put in that tunnel and chained,” mused the lad, as he looked at the iron still on his leg, “I might as well try to get back home. It’s pretty lonesome down here, and I don’t know whether I can signal any one or not. But it isn’t far to the mainland and I can swim it. Though if I’m going to do that I’d better file this iron off. No fun swimming with that bracelet on my ankle.”
He looked about for a place where he could sit down and file in comfort at the remaining evidence of his recent bondage when, as he approached the shore, he saw, pulled up close to a rude dock in a little cove, a small motor boat.
“Well, if this isn’t luck!” cried Tom. “There must be some picnic party here and that’s their boat. But no—wait a minute! Maybe it belongs to those men I heard talking in the tunnel. I’ll wager that’s it. And this is my chance! I’ll appropriate their boat since they treated me like a roughneck. I’ll get back home, maybe in time to stop their trick—whatever it is.”