"Shut up an' listen!" whispered Whipple. "They're talkin', an' mebby we can find out what their game is."
"There's the old quarry, on the right, Graydon," one of the men was saying, "and there's the canal on the left. Right around in here is where that air ship ought to be."
"Maybe we're too late, Harris," answered the man addressed as Graydon, "and that the game has been pulled off."
"I hope not. If anything has gone wrong with King and his friends, I'm to blame. Get out and cross the track to the quarry. Look around there and see if you can find anything of the boys. If you can't, my hands will be in the air, and I won't know the first thing to do. While you're nosing around the quarry, I'll walk over toward the canal. If anything has gone wrong with Motor Matt, I'll bet Hector Brady is back of it."
All this, which was plainly heard by Whipple and Pete, rendered them anything but easy in their minds. They knew Harris, the energetic officer from South Chicago, and his activities while helping Motor Matt had left memories anything but pleasant. And then, too, the mention of Brady had set the two scoundrels to guessing.
"We'd better duck while we've got time," whispered Pete.
"Wait!" returned Whipple roughly. "We've got ter find out what's up—it may mean success or failure fer that game we're workin' at La Grange."
"How ye goin' ter find out anythin' more? Them fellers have quit talkin'."
"They've quit talkin'," answered Whipple darkly, "but they haven't got away from here yet. Stick right where ye are, Pete, an' watch."
Graydon had got out of the automobile and started across the railroad track. It was only a moment or two before he was blotted out of sight. Harris had likewise climbed out of the car and was starting slowly in the direction of the canal.