"If 'Mr. Seven' will only stay around until this air circus is over Sunday I'll find out what's behind his mysterious coming to Atkinson," said Tim, who felt that "Mr. Seven" had challenged his ability as a reporter. On leaving the hotel, they parted, the chief copy reader returning to his bachelor headquarters and Tim and Ralph going to the _News_ building where they hauled out files of the paper and spread the heavily-bound books on their desks. "We'd better check together," suggested Tim. "Then there will be no chance of our missing a single tip." For an hour they poured over one volume, scanning each page and watching with especial care the picture page which was a daily feature. "I'm too sleepy to go on," said Tim when the city hall clock chimed eleven times. "Being outdoors most of the afternoon working on the plane gave me a yen for bed even though I want to keep on digging into the file. I might go right on over the very picture I'm looking for." Ralph picked up a telephone and called the Ransom House, where he ascertained from the clerk on duty that Mr G. Seven had indicated he would be a guest there for at least a week. Relaying that information on to Tim, Ralph added, "Now you can go to bed tonight and sleep soundly." They had just finished putting away the files when the door of the editorial room swung open and a stranger walked in. He was middle aged, with close-cropped, iron-gray hair, piercing blue eyes and large, capable hands. "I'm looking for Tim Murphy and Ralph Graves, flying reporters of the _News_" he said. "I'm Murphy," said Tim, "and my companion is Ralph Graves." "Then I'm fortunate to find you together. My card may give you some idea of what I want." Tim took the engraved piece of pasteboard and read the following words: "Henry Prentiss, United States Bureau of Narcotics." "I'm glad to know you, Mr. Prentiss," said Tim, "but I'm afraid your card hasn't given me any clue on what you're here for." "I understand the High Flyers and Ace McDowell are going to put on their air circus here Sunday under the auspices of the _News_." "That's correct, but no announcement has been made yet." "Then you're likely to have two stories for your paper next Monday, the actual story of the flying circus and the story of the arrest of Ace McDowell as the head of a notorious ring of dope smugglers." CHAPTER THREE The High Flyers The federal narcotic agent sat down on the edge of Tim's desk and smiled at the amazed expressions on the faces of the flying reporters. "Do you mean that you are going to arrest McDowell on a charge of smuggling dope?" asked Tim. "I'm going to do my best to take him in custody. He's a slippery customer but I think we've got all the evidence we need this time." "What a sensation this will make," whistled Ralph.