Harry Harrison 
Planet of the Damned 

Brion entered the temple and stood as if rooted to the ground. There was a horror in this place—it clung to everything. Muffled and hooded men stood silent and unmoving about the room, their attention rigidly focused on a figure in the center. Brion wondered how he knew they were men—only their eyes showed, eyes completely empty of expression yet somehow reminding him of a bird of prey. Then suddenly the figure in the center moved. It was a weird, crazily menacing action—and in an instant Brion knew he had found the enemy, the source of the evil that infected the PLANET OF THE DAMNED.