"A cart—that's what it is, and the sound we heard just before that was a man walking overhead. It's my belief that the place is immediately under the only street in Polkerwyck," declared Atherton.
With their staves, the Scouts sounded the walls, floor and ceiling. There was no trace of any secret openings. The walls were solid enough; only the distance between the dome and the open air was thin enough to enable the noise of the traffic to be heard with comparative distinctness.
"All right up there?" called out Phillips from the foot of the spiral staircase.
"Yes," replied Atherton. "We'll be with you in a minute."
"What shall we do with this lot?" asked Green, indicating the silver. "It's jolly heavy."
"We'll take it with us. We can put a few of the forks and spoons in our pockets and the bowl can be slung from a staff and carried by two of us. Mind how you carry it, Green."
As soon as the three Scouts returned to their waiting companions, the silver was distributed for the sake of easier carriage, and the march of exploration resumed. Presently, instead of continuing the upward slope, the tunnel dived with considerable abruptness. At the bottom of the dip there was water on the floor to the depth of six inches, while from the signs of excessive moisture on the walls and ceiling it was fairly conclusive that the whole of this portion of the tunnel had recently been flooded. A slight stream of water was still running from a fissure in the wall.
"This must be a proper trap in wet weather," said Phillips. "The water lodges in the dip until it soaks out again. That accounts for the fact that Tassh was unable to return to Polkerwyck House on the night of the storm."
"It certainly seems like it," said Green, as he splashed boldly through the water. "Doesn't it feel cold?"
From this point the tunnel again sloped upwards, in places so steeply that the incline had to be broken by short flights of steps.