Spartan 117 (firstname.lastname@example.org) writes:
...With a race like the Flood, a single ship is the begining of the end. The race that started exploring the world that the Flood originate from probably fell victum to the Flood themselves. Now say they only brought one ship with them and 40 of them were on it. Now that one ship and those 40 hosts are out in the galaxy. They land on a world and the spores disperse among the populace. That is a world that can only be Reclaimed by quatentining it and burning every potential host the Flood could take. But, say those military forces that land there either don't know that is the only way to contain the disease or are unwilling to slaughter those thousands or millions of creatures. Then the world provides a lot of host bodies, but more importantly, a lot of ships. These ship baring Flood scatter to the wind and one shows up on this world, another here, another there. These worlds fall and very quickly it becomes all but impossible to destroy this force that is so deadly not because of they military might that it imploys, but because that it is so multaplicative. It only takes a very small amount to start, but that sets of a chain reaction that unleashes countless thousands.