I don't know how many of you here would be familiar with the two
short-lived American sci-fi series, "Dark Skies" and "Prey". "Dark Skies" was a
show set in the 1950s (or thereabouts - not 100% sure what the year was supposed
to be). It basically followed around a couple of government agents who were
actively conspiring to hide the existence and interference of extraterrestrials
in Earthly affairs. "Prey" was a show on which a competing species of human
being had been discovered living among us, a competitor bent on eliminating us
from the gene pool. On the show, the "other" humans were scientifically
advanced enough that they could take a "normal" human and perform a complete
genetic makeover in order to turn a normal human into one of them.

Okay, that background out of the way... Suppose you were to somehow
find out that extraterrestrials really are visiting Earth regularly, and have in
fact begun "assimilating" humanity into itself via a gradual meshing together of
the two species DNA. You find that the activity is taking place in secret, and
your knowledge of it will never reach the mainstream. You're given one of two
options: 1. Let the aliens give you a "genetic makeover" as on the show "Prey",
thus turning you into a human/alien graftbreed, or 2. Die.

If you choose 1, you won't have to help them carry out their takeover,
but you will have to keep quiet about it. It's also demonstrated to you that
your own core "self" wouldn't change very much. Your physical endurance would
increase exponentially along with your intelligence, but you'd still feel like
"you". I.e., if you loathed the aliens before the transformation, you will
continue to loathe them afterwards - they don't alter your mind, just your body
and the genetic heritage you'll leave with any offspring you may subsequently
produce.

The only "behavioral" modification they will make is that they will
render you incapable of revealing your knowledge of the situation (you can think
about it to yourself all you want, but the moment you go to express it in any
way, you'll suddenly find yourself forgetting what you were about to express).

They're taking over not only our world, but our entire species. Would
you go with the makeover? Or would you choose death?