Structural engineer Steve Burrows takes his team of laser-scanning experts to St Paul's Cathedral in the heart of London. They venture inside the majestic dome to explore its groundbreaking three-part structure; determine how the cathedral's architect, Sir Christopher Wren, overcame unstable foundations and immense structural forces to support his dome; and investigate how the cathedral survived a direct hit by a German bomb during the London Blitz. The laser scans produce genuine revelations and give the team new insight into this iconic architectural masterpiece.