THE SECRET OF THE HOLD
In response to Ned's hand on the lever, the water door closed and the pumps in the next compartment soon cleared not only the sea vestibule but the tanks of the submarine of seawater.
In a moment the Sea Lion lifted to the surface, and Ned lost no time in relieving himself of his helmet. Then, still attired in the rubber suit, he hastened to the conning tower, where he found Jack, glass in hand, sweeping the moonlit sea eagerly. There was a faint haze off to the west, but nothing more. Whatever had passed above the submerged boat, on the surface, had wholly disappeared, though the time had been very short.
"What did you see?"
Ned asked the question because Jack's manner indicated excitement, if not anxiety.
"Just a shadow," was the reply.
"It might have been a shadow, passing over the moon, the shadow of a cloud, or a cloud itself," suggested Frank, sticking his head out of the hatchway.
Ned pointed to the sky. There was not a cloud in sight.
"It must have been something of the kind," Jack mused, "for no boat could get out of sight so soon."
"Not even a submarine?" asked Ned.