For thousands of years, man has been evolution's greatest creation... until now.
A virulent new disease is killing the children of Manhattan and has reached epidemic proportions. Peter Mann in desperation asks the entomologist, Dr. Susan Tyler, if she can help by killing the disease carrier, the common cockroach. Susan genetically engineers a new species of predatory insect to exterminate the cockroach and then die off. This novel solution works and the children recover but nature isn't the laboratory and things don't exactly go according to plan. Three years later people start to disappear, mutilated bodies are found and wild rumors of giant insects mimicking man start to emerge from the bag people living in the subway under Manhattan. Peter and Susan are called in to investigate.