While a good class with a guest speaker requires plenty of advance preparation, the real clincher is for the teacher to create a tight fit between the course objectives and the speaker's purpose in being there. The speaker has to play an essential role in fulfilling the learning objectives of the course; if that doesn't happen, the students will have little incentive to take advantage of what guest speakers can bring to a classroom, and the guest speakers won't understand what they can contribute. In this article, the author shares his experience on what went wrong when he invited a visiting writer to his class.