Suddenly Bob, who was walking a little in advance, called out:
“Move? Where?” inquired Jerry, with a laugh.
“On the airship. I’m sure I saw some one on deck.”
“Maybe the professor is aboard?” suggested Ned.
“No, there he comes now,” said Tod, pointing off to the left, where the scientist could be observed stalking across the sand, his net over his shoulder, and his green specimen box dangling at his side.
“Somebody surely is on board,” insisted Bob. “I saw him move again.”
“That’s right,” agreed Nestor. “I saw something move, too, then.”
They quickened their pace, and in a little while they were near enough so that all five could observe some shadowy form moving about on the after deck.
“If it’s a man, he’s going about on all fours,” said Ned.
“Perhaps it’s Mr. Bell,” came from Bob. “Maybe he’s gone crazy from the heat.”
“Nonsense!” exclaimed Jerry, breaking into a run. The others followed. But when they were within a short distance of the craft they came to a sudden halt.
For from the airship there now came a series of ugly snarls and roars.
There was no need to answer him, for a moment later there sprang into view, in the background of a vivid sunset, a big mountain lion, who paced back and forth on the forward deck. The beast was in possession of the _Comet_.
“Come on! We must drive him out of there!” cried Bob. “I left a lot of opened cans of food in the kitchen, ready for supper, and that beast will eat ’em all up! Come on, we must drive him out!”
“Hold on!” exclaimed Jim Nestor, catching Bob by the shoulder, as the impetuous youth was about to dash forward. “You don’t know as much about them critters as I do, son. Keep away as far from ’em as you can, especially when you haven’t got a gun.”
“Haven’t you got your gun, Jim?” asked Tod quickly.
“Nope. First time I’ve been without it in a long while,” and the old miner looked at the place where his big revolver always hung in its leather holster.
“Same here,” added Nestor. “We were foolish to come away without them, but it was so hot to pack ’em over the desert, and I didn’t think anything would happen.”
“Me neither,” agreed Tod. “That critter must have been passing, and smelled the meat tins. It concluded it liked the airship, and it’s making itself to home,” for the beast was leaping about from deck to deck, passing through the cabin and engine room as if it belonged there.