A group of scientists have been commissioned to create a new kind of super soldier. As this project includes illegal human experimentation, the government wants to limit the risk of anything being traced back to them, selecting disposable people for the process. Illegal human immigrants from Latin America, fleeing from violence and poverty in their home countries and hoping to obtain a green card, are chosen for the project with promises that they would earn passage into the country and given permanent residence. This is provided they cooperate and agree to participate in the experiment.
In order to create a new hybrid species, a group of scientists combined eldritch DNA with human embryos and inserted them into these surrogate mothers.This decision was a mistake in retrospect, as the unborn child was able to alter the DNA of its mother, twisting the body into horrific new forms. The affects on the host varied depending on the fetus's goals. These hybrids manipulated and molded their hosts to better accommodate its size and shape, outfitting it with natural weapons in order to to better defend itself and the host. Whatever dark goals these alien children had in mind are unknown, as all the scientists were slaughtered by the brood mothers, who left the facility to sire their children in parts unknown.
After the incident, the government sent a special team in to try to piece together the events and what led up to them. How would a fetus be able to change or manipulate the DNA of its host?