Though the original steps for invasion in secret may have been a straightforward and unified effort for the alien society, the move to include humankind in the plan led to infighting that would ultimately undermine all their efforts and lead to all out civil war.
Conscientious objectors – As more and more aliens (or alien clones) entered into a disguised life among humans, there were many who developed both an empathy for humans and a disgust with their apparently dictatorial society. Some wanted to simply break away and blend in with life on Earth. Others wanted to undermine the deadly aspects of the invasion plan and even pursue their own ways to hijack the plan in secret. We encounter several of these individuals and their stories along the way. In an effort to control these incursions, alien bounty hunters [who for some reason all used the same morphed face] were sent to track down and kill these ‘traitors’.
Rebels – Far from controlling dissension, the aliens instead faced a growing faction of rebels who began to destroy the carefully worked plans of the larger species for reasons that are still not entirely unknown. These aliens did not bother working in secrecy. They openly burned masses of people who either were abductees or worked for The Syndicate. They had to morph into faceless beings to prevent their enemies from using the black oil as a weapon against them. This turned into a civil war of sorts. In one of its largest coups, the rebel alien force killed the entire leadership of The Syndicate and presumably Cassandra Spender–the first successful alien-human hybrid. Thus, they pushed the larger group of aliens and their colonization plans back to square one.
Alien replicants – As a pushback to defeating the rebels, the alien leaders activated a new brand of ‘aliens’ that were the results of years of alien-human experimentation on harvested human ova. Unstoppable killers in the guise of humans, these alien replicant ‘super-soldiers’ were a double edged sword; driven by instinct to kill to protect the alien plans, they would destroy human and alien alike who stood in their way. The first wave had been soldiers that were soon placed as key operatives in the CIA and other agencies. The second and larger wave were to have been alien abductees forcefully infected and turned into replicants. (The only reason this did not develop in full was the work of an alien dissident with the ability to heal known as Jeremiah Smith who, with the help of a crazed UFO cult leader, would track down the infected abductees and cure them before the virus could develop.) With the intervention of these ‘super-soldiers’, the original plans for colonization were back on track.