For over a century two rival organisations of women have gone to deadly lengths to secure a precious scrap of fraying embroidery in the hopes of finding the original medieval manuscript from which it was torn. There's the Order of St Katherine: devoted to the belief that women must pull strings in the shadows in order to exercise covert control. And the Fellowship of the Larks: determined to amass as many overt positions of power for women as possible - while making sure their methods never come to light. When trailblazing paleographer Dr Anya Brown is headhunted by the exclusive Institute of Manuscript Studies at St Andrews, she's unaware that she is in grave danger - her new employers are the Larks, and they'll stop at nothing to achieve their mission. As Dr Brown is drawn deeper into this ancient web, events spiral beyond her control.