“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.
“He's a friend of mine” she said, “and I never go back on a friend.”
“Well,” he replied jokingly, “I can't imagine a friend going back on you. However, I'll not be curious about this chap. He appears contrite, and the incident is closed. But all the same, this is one of the queerest cases I've had in all my experience,” and he went out, still puzzled.