Final answer:
The provided text excerpts do not contain information about secret passages that Mr. Andrews showed George on blueprints. Additional context is required to accurately answer this question.
Step-by-step explanation:
The secret passages that Mr. Andrews showed George on the blueprints are not explicitly described in the excerpts provided. These excerpts describe various settings and allude to intricate architectural designs and hidden aspects of a building or house.
However, these passages do not contain specific information regarding Mr. Andrews, George, or blueprints that detail secret passages.
To answer such a question accurately, we would need additional context or text that directly references the secret passages shown on blueprints. Without this information, we cannot provide a precise answer to the student's question.