Engineer Rob Bell tells the story behind the design and construction of Isambard Kingdom Brunel's famous bridge over the picturesque Avon gorge at Bristol, and discovers that some people question whether it was entirely the product of his own devising. The bridge remained unfinished in Brunel's lifetime, but when he died in 1859, his friends decided that the bridge should be completed as a memorial, using the chains from another of his suspension bridges that was being demolished.