When Dax and Worf were married, Worf was a member of the House of Martok. This meant that Dax needed to get the blessing of Martok's wife, Sirella. The tradition-bound Sirella insisted that Dax be able to recite Klingon history - and the history of the House of Martok. Dax studied this beautiful prop book, designed and detailed by John Eaves.