Final answer:
The shuddering old man who crouched alongside Alfred's stairs is a mysterious character in a piece of literature.
Step-by-step explanation:
The shuddering old man who crouched alongside Alfred's stairs is a mysterious character in a piece of literature. Based on the given excerpts, it's difficult to determine exactly who he is and what he wants without more context or specific information about the text. However, it is clear that the old man elicits fear and curiosity from the other characters. To understand his role and purpose in the story, it would be helpful to analyze the text further or provide more specific details about the literary work in question.