The Emperor's Plague (Star Wars: Young Jedi Knights, Book 11)

Bornan Thul's secret is out: he's protecting a deadly plague that could devastate the galaxy if released. And the evil Nolaa Tarkona--leader of the Diversity Alliance--knows where it is hidden. Now Jacen, Jaina and their allies must race against time. As a massive battle rages between New Republic soldiers and the forces of the Diversity Alliance, the young Jedi Knights must find and destroy the plague before it can be released.