“I will try to,” said Frank. “When are you going to bring action?” “To-morrow morning!” “All right; I will try and do my part.” Frank went back to the Steam Man and narrated the plan to Barney and Pomp. The two faithful servitors listened with the deepest of interest. “A’right, Marse Frank,” declared Pomp. “We’se jes’ de chickens what can gib dose greasers a lickin’.” “Bejabers, we’ll thry it,” said Barney. Nightfall was at hand, so it was decided to make camp upon the spot. The prospectors had decided not to start upon their invasion of the greasers’ stronghold until the next day. Darkness settled down thickly over the plain. It was near midnight before all was quiet in the camp. As the prospectors had a picket line out, our travelers did not deem it necessary to set a watch. So all turned in and sought slumber. But Frank Reade, Jr., was utterly unable to sleep. He tried in vain to woo the gentle goddess. A premonition of some mighty peril was upon him. At length, as his nerves grew more acute, he decided to get up and walk in the air in the hope of inducing slumber in that way. He did not arouse Barney and Pomp, and quietly left the wagon. He passed through the camp and came to the banks of the creek. Just as he reached this point he fancied that he saw shadowy forms moving a short distance out upon the prairie. Frank’s vision was unusually keen. He became convinced, after a brief time, that he was right. It seemed as if the prairie in that direction literally swarmed with men. They were creeping noiselessly along over the soft grass. A chill of terror seized Frank Reade, Jr. He thought of the greasers. Might it not be a band of them intent upon attacking the camp? The more he pondered upon the matter the more convinced he became that such was a fact. But one thing puzzled him. The prospectors had appointed a very strong picket guard. How had the greasers managed to pass them? This was a question not easily determined at that moment. It was possible that they had silently overpowered the picket, or that the latter had slept at his post. In any event the enemy were creeping up to surprise the camp. The realization came upon Frank Reade, Jr., with a force which for a moment seemed likely to overwhelm him. “My soul!” he gasped. “They will be upon us before the alarm can be given!” It was easy to foresee the effect of such a surprise upon the prospectors. They would, no doubt, be cut down before they could really prepare themselves for the onslaught. In that moment a dozen daring schemes flitted through the brain of the young inventor. He thought of starting the Steam Man out amongst them with a view to breaking up their advance. But the creek was between, and it would be some trouble to find a fording place. Under the circumstances Frank executed the most sensible move that he could. He stole quickly back into the camp. It was but a moment’s work to silently arouse Silver Sam and Diamond Jake.