“Not much for me,” Mason said. “It’s really for you.”
“What do you mean?”
Mason said, “I’m not going to mention names, Mattern, but the claim has been made that you left the broker’s office right after the completion of that stock deal and went out to report to Tidings, and while you were talking with him, there was a quarrel, that Tidings accused you of having a personal interest in the transaction and confronted you with proof, and that you shot him.”
“That’s absurd,” Mattern said.
Mason nodded affably. “Thought I’d mention it to you,” he said, “so you’d have a chance to clear it up.”
“In the first place,” Mattern said, “I can account for every minute of my time from the time I left that brokerage office.”
“That’s fine,” Mason said. “Would you mind running over the schedule with me?”
Mattern took a notebook from his pocket. “Not at all,” he said. “When I realized that it was going to be necessary for me to remember what had happened that day, I thought I’d better jot it down on paper.”
“Good idea,” Mason said.
“To begin with,” Mattern said, “I left the brokerage office at eleven-eight. I made a point to notice the time when the deal was closed. I returned to my office, and Mr. Tidings called me just about noon. I told him that the deal had been concluded satisfactorily. Mrs. Tump had been trying to see him, and I told him about that. Then I rang up a friend of mine in one of the other offices and asked her to have lunch with me. We went down in the elevator at five minutes past twelve, and I returned with her at five minutes before one o’clock.”