Working With the Enemy - Book 3 in the Chronicles of Samantha Shepard

After disappearing for two years and waking up amidst an age-old enemy, Shepard fights to regain what she has lost - the trust of the Alliance, some of her dearest friends and her lost love. With a new Normandy, a Cerberus crew and self doubts raised by the improbability of her own continued existence, Shepard must battle humanity's newest emerging enemy, the Collectors.