The head of Petrie's Island, Roger Campbell was the oldest and wisest of Petrie's farmers. The islanders looked on him as the man to turn to in a crisis. Although lazy-eyed, slow, and seemingly ignorant, Campbell was actually a very intelligent and capable man. When Peter Argyle came to him with news of bizarre happenings on the island, Campbell soon learned that many of the farmers had been finding dead, boneless livestock on their lands. Trying to track down Dr. Reginald Landers, Campbell and Argyle learned Landers had been killed and that genetically-engineered monsters, the silicates, were loose on Petrie's Island. It was to Campbell that Dr. David West and Dr. Brian Stanley turned for help in setting up defenses against the Silicates, and Campbell proved more than up to the task.