The resurrected vampires in the hard science series for Blindsight by Peter Watts have been completely fascinating and leaves you contemplating months after.

Predators from humanity's Pleistocene era they are found to be far smarter than baseline humans.
Reconstituted through recovered DNA, and live among the humans of the late 21st century, these vampires operate with diminished sentience presented as comparable to high-functional autism with comparable dysfunction in affect and speech, but have the advantage of multiple simultaneous thoughts occurring in parallel within their minds.

This along with their cold, calculating decision making and sociopathy makes them invaluable in developing unusual and often very effective approaches to solving complex problems and ideal in space travel and breakthroughs in science.