A virulent plague has stricken Terok Nor, striking down both the enslaved Bajorans and Cardassian oppressors, who blame each other for the growing epidemic. Dr. Katherine Pulaski, late of the Starship Enterprise, must work with the tyrannical Gul Dukat, as well as a rebel spy named Kira Nerys, to discover the true source of an infection that threatens them all!