“A passenger. His name is T. Morgan Carey, of Los Angeles. He is rather prominent in business circles--a pretty sane, careful man, and his testimony would have considerable evidence with a jury.” “Find out from the messenger if Carey identified Bob--I mean Mr. McGraw (the detective smiled slightly) before the messenger gave chase to the hold-up man, or after he returned with the hat. If the latter, I can explode his testimony. I happen to know that Mr. Carey is a business rival of Mr. McGraw's and very unfriendly to him. It would be to Carey's great financial advantage to see Bob (again the detective smiled) in jail. Then ask your agent at Keeler to make inquiry and learn if a tall young man with auburn hair didn't ride into town the day following the hold-up, mounted on a roan horse. If he sold the horse, saddle and spurs, purchased two burros and outfitted in Keeler for a prospecting trip, that man was Mr. Robert McGraw and he didn't arrive bareheaded. I think you'll discover that you're following a false lead.” The detective could guess a thing or two; otherwise he would not have been a detective. He guessed something of Donna's more than friendly interest in the man he was after; an interest which he felt to be greater than a mere feeling of gratitude for what McGraw had saved her from, and his sympathies wore with her. She had been “open and above board with him” and he appreciated the embarrassment that might attend should the matter be given publicity. “Whatever I discover will not be made public, Miss Corblay. Thank you.” He lifted his hat and walked out, while Donna, selecting one of the late magazines from the news-stand, sat down and read for the rest of the afternoon. Eight days passed before the detective appeared again at the counter. “Miss Corblay,” he reported smiling, “you're a better detective than I. McGraw didn't do the job--that is, your--Bob. But some other McGraw did. The fact is, he's sent back the money he lifted from the company and the passengers. At least, a number of them have reported the return of their cash. Here's a note the agent here received a little while ago.” He passed a type-written sheet across the counter to her. Donna read it carefully. “The plot thickens. However, this is only added proof that my line of reasoning is correct. This line, 'I didn't have no business to do it in the first place,' clinches the testimony. The Robert McGraw of my acquaintance never uses double negatives.” “And he couldn't have arrived in Goldfield with a burro train in less than six weeks. You say this man uses double negatives. There's a clew. Who, among your acquaintances, Miss Corblay, uses double negatives?” “Every soul with the exception of Mr. McGraw” replied Donna. “Following a clew like that in San Pasqual would be like looking for a needle in a haystack. But I think I could name the man who wrote that note.” “Who is he?” Donna favored the detective with a mocking little smile.