You are in your office; the door is open. A well-dressed visitor walks in confidently without knocking. He has a single sheet of wrinkled paper in his left hand and an open brown envelope in his right hand. Without any introduction, he strides to your desk and carefully places the paper and envelope on top of the ungraded midterm exams and unfinished referee reports. Glancing at the paper, you see a red "Eyes Only" stamp and a complex 7-by-7 matrix; visible in the envelope is an untidy mess of $100 bills. "Tell me about that matrix," he says. How do you respond?