These necrotic sacs are fascinating. Disease is not uncommon in necromancy, but it's almost always a mundane side-effect of natural decay. Not so here. I can say with certainty that these sacs are not a natural side-effect. They were specifically designed to produce and excrete infectious fluid. Given that I've never seen this infection before, I've elected to name it: Necrosepsis Imperialis. Transmission seems clear enough. The sacs develop beneath the carrier beasts' skin and swell over the course of several days. At some point, a pore opens to allow for slow secretion. As far as I can tell, this lasts for only a few days before the sac ruptures under pressure. Given the thickness of the colossi's skin, it's probably an explosive event. I've not seen it happen yet. More's the pity.
The disease moves quickly. From the bodies I've examined, I'd say that the period between infection and death is something like two to three days. It presents similarly to the latter stages of the Knahaten flu, with some notable differences. For instance, instead of bloody effluvium, the victims secrete a black tar-like substance from the eyes, nose, and mouth. There is also evidence of violent spasms. The most notable difference, however, is the rapid swelling of the body post-mortem, and the appearance of small pustules on the skin. The liquid produced by these sores is incredibly virulent—far more dangerous than the fluid carried by the colossi and hoarvors. Obviously this makes it imperative to halt the disease at its source, before it can incubate and mature. Now if only I could think of a way to do that.
