“Turn around and look, if you don’t believe me,” Clay shouted.
Case turned about on his seat, letting the oars lie idle in the waves for a moment, and fixed his eyes on the deck of the Rambler, now not more than a hundred yards away. Captain Joe was barking like mad on the deck, advancing to the west rail, as if pursuing some one, and then retreating, as if being beaten back!
While the boys looked, he crossed the deck half a dozen times, snapping and snarling at something not in view from the small boat. Whenever he retreated he seemed to be cringing as from a blow! The boys looked on in wonder and fright. The dog was fighting the air!
“Not a thing in sight!” Case commented. “A boat sliding along with no one near her, and a dog barking at nothing at all. I give it up!”
“Let me row,” Clay suggested. “You must be getting tired.”
Case dropped off the seat backward and Clay took up the oars.
“Tell me what you see,” asked the latter, after rowing a moment.
“The dog has gone back to his corner,” Case reported, “and Teddy is doing the investigating. The Rambler is still jerking in shore, and there’s not a soul in sight! Ever hear of invisible men and things? Well, that’s just what we’re up against!”
“Alex is invisible, all right!” grunted Clay. “See him yet?”
Case did not answer. Instead he dropped into the seat beside Clay, almost overturning the frail boat before he succeeded in getting into action with one of the oars. It was a minute before he spoke in explanation of his conduct.