Jonathan climbs the dreaming spires of the College to investigate how the devastation of the Black Death led to an architectural innovation. He tests his newly acquired climbing skills by scaling almost 100 feet to reveal how the enduring symbol of university life - the quadrangle - originated here. On his climbs, he discovers the bishop whose vision it was and sees how he literally left his mark all over the college in a medieval PR stunt; discovers carvings of English folk tales in the chapel; and traverses a sheer drop of 80 feet to explore how a new glazing technique, known as 'yellow stain', allowed New College to create some of the most magnificent medieval stained glass in the country.