When a cockroach-spread plague threatens to decimate the child population of New York City, evolutionary biologist Susan Tyler and her research associates rig up a species of "Judas" bugs and introduce them into the environment, where they will "mimic" the diseased roaches and infiltrate their grubby habitats. So far so good...until the bugs keep on evolving and learn to mimic their next prey--humans. Noirish, dazzling production work ensconces reliably creepy bug-related thrills. Based on the short story by Donald A. Wolheim.