All hands agreed with the professor, and then Van dismounted, and, striking a match, held it close to the ground.
He could see the fresh prints of horses' hoofs very plainly, and this told him that Doc Clancy and the troop of horses must have gone through the gateway.
"We must open the gate," he said, rising to his feet. "Come! we will see if it is possible to do so."
Van had scarcely spoken when the huge, iron structure swung noiselessly open, as if by magic.
In an instant our hero was upon the back of his horse.
"Come!" said he. "We may be going into a trap, but I am ready to take the risk. Will you follow me?"
"We will!" came the reply from all hands.
The next moment the boy urged his horse through the gateway, and his companions boldly followed him.
As soon as the last one was through, the gate swung back to its former place, making no noise whatever.
"I don't like this business," observed Lank Edwards, with a shake of his head. "It looks as thought ther old boy has got somethin' ter do with this place. Howsumever, I'll stick to ther crowd."