Adam Hart, also known as Arnold Nordland, is the main antagonist of the 1968 science fiction film The Power and the book of the same name it's based upon. He at first appears simply the local military liaison officer, for a military think tank that the protagonist works for, but is really a man born with a mind so powerful that mind, matter and even reality bends to his will, he begins killing to protect his idenity and remove his rival.
Following the tests, Dr. Henry Hallson discovered one member of the group possessed an incalculably and superhumanly powerful mind. As the tests were done anonymously Henry had no way of knowing which member it was, so he tried a test using a psi wheel, when the genius refused to reveal himself, he suggested they all concentrate and let the genius remain anonymous and as such the wheel began to move, first slowly then faster and faster. For this discovery Adam killed Henry with telekinesis; however Henry had time to scrawl on the wall his name as a clue before he died. As Henry was a childhood friend of Adam, he realised just before he died, it was him who was the genius.
The next day Professor Jim Tanner (the protagonist) was called by the police on suspicion of being the murder, Adam had already wiped the minds of his degree granting colleges, meaning he appeared to have commited academic fraud.
Adam then directly assaults Tanner, first teasing him by making simple alterations to the landscape (causing a stop sign to change don't walk to don't run) before forcing him through a series of mind breaking illusions and peaks of human endurances bringing him to the point of death, however Tanner survives. Now well aware of the dangers Adam possess, Tanner leaves and tries to track down Adam before he tries again.
Arriving where Hallson grew up, Tanner learns that Adam was a local boy, who was renound for both his great intelligence and his power over women. While there, Tanner is almost killed by another local, who Adam gave instructions to kill anyone who came asking about him, on threat of death.
Upon learning more on Adam's origin Tanner returns and tries to find out more from Hallson's window, but Hart got there first, and had already wiped her memory of her husband and removed all evidence of his existence. Hart then turns on another scientist Melniker, but first teases Tanner, by publishing "Don't run" in the headlines of the papers. He then kills Melniker.
Hart then tries to kill Tanner again, by this pretending to be under attack from him himself, tricking Tanner into entering an elevator shaft where he tries to crush him with the elevator. But once again Tanner manages to escapes at the last moment. Adam (still pretending to be Arnold) then pretends to join them and urges Tanner to kill the remaining two suspects, but Tanner refuses, knowing one of them is innocent.
Tanner next tries to talk to Dr. Van Zandt looking for answers to which on is Hart, but after talking to his wife, Adam tries to run him down in his car, Tanner manages to escape. But Adam manipulates Tanners own car so that it goes out of control and crashes into the river when he tries to drive awy. Tanner once again manages to barely escapes with his life. Adam meanwhile sets Van Zandt's house alight and traps Van Zandt and his wife inside, killing them both.
After confronting Scott the last remaining scientis (who has gone mad, believing it to be Tanner who is the genius), Tanner realizes the truth and finally decides to confront Hart himself in laboratory. His ruse revealed, Hart drops he act and lets the full power of his mind loose on Tanner, making him experience incredible extremes: freezing cold, burning heat, before finally the darkness of space once again bringing him to point of death.
However at the last moment, in Tanners mind everything snaps and he realizes that Adam wasn't the genius found by Henry, for why would someone who had been so careful all there life expose themselves now? The Genius was Tanner himself. Explaining why he was able to resist Adam's attacks when all others died, and why Adam targeted him since the beginning, he was trying to remove his only rival.
Realizing this Tanner begins to fight back, unprepared for this, Adam is backed into a corner. Unable to take the strain, he was killed by Tanner telekinetically squeezing his heart, thus ending his murder spree.