The Puppet Masters

Soft and clinging, it snuggled up against him, mute and warm. He felt perfectly happy in a mindless sort of way.
Quite mindless.
The alien clutched and settled, flesh to flesh, tapping into his nervous system, feeding its commands into his brain. He felt nothing, had no worries. He belonged, body and soul, heart and mind to the slug-like creature. He felt he was safe; among friends. Hundreds, then thousands of them, all taken over by the creatures that had come pouring out of the spacecraft.
Happy and safe - and doomed.