Tamper is about a boy named Whit who grows up in the 1960s obsessed with paranormal research, B-movies, and strange noises drifting up from the basement of his parents' house. By the mid-70s, he is experimenting with drugs and seeing a psychiatrist, trying to solve the mystery of his obsession with the number 4. Whit and three friends meet a reclusive mystery writer who hints that the answer may be found in the ancient burial chambers under the island of Malta, where, according to an actual 1940 National Geographic article, a field trip of children and their teacher disappeared and were never seen again. Tamper was the word used by pulp science fiction writer Richard Shaver, who sparked a controversy among the readers of Amazing Stories Magazine in the 1940s when he claimed that an ancient civilization of underground mutants were tormenting his mind with invisible rays, "tampering" with his brain.