Cameras for the first time go behind the doors of the Grand Masonic Lodge of Scotland, in Edinburgh, the home of freemasonry, and lift the veil on the inner secrets of this normally closed world. With exclusive access to its 400-year-old archive, its members around the country and its grand master, who presides over 1,000 lodges and 100,000 Scottish Freemasons worldwide, we film at lodge meetings, the selection of new candidates and the installation of grand masters.