"From all I can gather from these," explained Ralph, "the man who ran away with the old engine was Rivers. This book bears his name. From it I would think he was receiving a goodly sum each week from some mysterious source for 'looking after' the Great Northern, as it is expressed." "This is the underhand work of our rivals in business," declared the assistant superintendent bitterly. "I think so, too," assented Ralph. "Outside of that, however, it is certain that Rivers and his fellow conspirators are doing some business 'on the side,' as he again aptly expresses it in his notes. A letter will show you that a man named Kingston hired him to wreck the two cars near the quarry." "Kingston, the contractor? Why, it was his own machinery. He had a large contract to do some extensive blasting work for the Great Northern," spoke Adair. "Yes," nodded Ralph, "I guess that from what the memorandum book tells me. The contract, however, had to be done in a certain time or Kingston forfeited a heavy bond, I believe." "That is true," said the superintendent. "He found out that his machinery would not do the work and that he would lose on his contract." "And wrecked his own plant!" exclaimed the assistant superintendent. "Incredible!" murmured the head official at his side. "You deserve something for ferreting that out," declared Adair approbatively. "There is your evidence, gentlemen, it seems," he added, pushing the documents over to the others. "This is getting pretty serious," observed the superintendent. "I will hunt up the contractor," said Adair, making a note. "I have men looking for Grizzly and Mason. The other suspects in the service are being shadowed. I think, with the start this famous young friend of ours, Fairbanks, has given us, there will be a general clearing up of the situation in a short time. Dallas is in the company and confidence of the conspirators. There will be some arrests and confessions within a few days. I think I can safely promise that." Ralph listened attentively while the others engaged in a general discussion of the situation. It was arranged that he should resume his position at headquarters in the office of the chief train dispatcher. Adair was to go down the line for the avowed purpose of getting more closely in touch with his faithful young assistant, Zeph Dallas. The latter, through the exercise of a keen intelligence and perseverance, seemed to proudly hold the key to the entire situation, and Ralph was glad of it. "There is one other subject of importance," remarked the road officer, as the superintendent arose and the conference seemed as on end. "What is that?" "The pay car affair." "I thought that was all arranged." "It is, so far as we are concerned, but shall I advise Fairbanks of the arrangements?" "By all means," directed the superintendent promptly.