An insane scientist tests an invisibility serum on himself and becomes a threat. His co-workers must stop him. The story recaps the movie "Hollow Man" from 2000, where scientist Sebastian successfully reverses the serum's effects on an invisible gorilla, Isabelle, but she has a heart attack. Sebastian revives her with a stimulant, and the reversal serum works. Sebastian tries to rekindle a relationship with Linda but fails, not realizing she is dating Dr. Matthew. Sebastian lies about the experiment's success and plans to test the serum on humans, starting with himself. Despite objections, the Pentagon approves. The test results in Sebastian experiencing extreme pain and a cardiac arrest, putting his life at risk.