A storyteller builds a narrative that captivates the audience, immersing them in the story. Storytelling is an interactive process. Though the listeners cannot affect what happens in the story, a good narrator observes the audience's responses and adjusts his/her storytelling accordingly. We present an automated storytelling agent that is aimed at achieving the same effect. While presenting a story, the user is given chances to give comments or ask questions. The agent estimates the user's preferences towards various topics from these responses and weighs the factors of novelty, current interest, and consistency for generating the next part of the narration. We describe the components of the agent, and an example of applying it for narrating a Chinese fantasy story.