A user provides the following text to a language model, hoping it will continue the story: 'The old lighthouse stood alone on the cliff, its beam cutting through the thick fog. A ship's horn blared mournfully in the distance.' The user is disappointed with the model's output, which is short and lacks a clear narrative direction. Based on the principles of crafting a complete and effective prompt, identify the two main components that are missing from the user's input and explain why their inclusion would lead to a better story continuation.