(W) George Mann (A) Emma Vieceli (CA) Rachael Stott. The eighth Doctor and Josie Day start a universe-wide investigation! First stop ? Lumin's World, home to a raging war between the near-extinct Calexi and the crystalline Spherions! When Josie is wounded in the crossfire, it's up to the Doctor to strike a peace ? and find a cure ? before she dies!