[[caption-width-right:300: Now you see him, '''NOW YOU DON'T....''']]
* The entire premise of the film, which has loads of ParanoiaFuel and FridgeHorror aspects to it. An already-unstable scientist uses a serum to become invisible and as a result [[WithGreatPowerComesGreatInsanity loses his sanity completely to the point of becoming an]] AxCrazy sociopath.
* There's also the fact that throughout the events of the film, no cure/ability to reverse the effects of the serum is able to be created/found, despite the attempts of his fellow scientists who he eventually turns against. And that's not even going into the implications of what one would do while invisible or what would happen to one who was unwillingly stuck with such a person without their knowledge. Special mention goes to one scene in which the VillainProtagonist, fully invisible, spies on his female neighbor and ''rapes'' her.