Desdemona, called Dess for short, is a polymath, which in these books means that she has an inherent aptitude for mathematics, not the usual definition of polymath. Her skill with numbers is seemingly unparalleled. In the books, it is even suggested that ability is so extensive that she can process mathematical data at a greater rate than even a regular computer. Throughout the series she uses this ability to deduce the "shape" of the Blue Time, allowing her to predict abnormalities in the fabric of time and space within midnight. Along with her skill at mathematics, she is also easily able to locate and identify thirteen letter words. As a result, she is the group's expert on anti-darkling defence and weaponry. Dess's power is useful in both the Blue Time and regular time. Dess has dark brown hair and eyes, with olive skin.