It was with some feelings of apprehension that the others watched as Old Billee reached for the copper lever and pulled it toward him, It operated as easily as it had for Bud.
And almost as quickly as had taken place on the other occasion, there was that roaring, rumbling sound, a noise as of the blowing of a great wind, and then the waters began to rush back into the pool.
"Here they come!" yelled Dick, as he stood beside Bud on the rock.
Truly the waters were returning as the hidden gate was closed when Billee pulled the lever.
Would they go down again?
That was what each one asked himself.
CHAPTER XXIII
THE CONSPIRATORS
Rapidly rushing, foaming, bubbling and boiling, the waters rushed into the mysterious cavern, until they again filled the pool across which Bud and Dick had swam to the rescue of Nort on the rock. Now the situation was reversed. It was Nort who was on the mainland, or shore, so to speak, and the others who were on the rock.