Dr. Simon van Gelder (Morgan Woodward) escapes a penal colony on board the Enterprise by way of a cargo box transported from the planet. He seems to be a mad, violent escaped lunatic who could leave a body count on the ship but there's a definite motivation in his actions, making it to the bridge, having taken a phaser from an officer, and demanding asylum from Captain Kirk. After being subdued by the Vulcan neck pinch from Spock, McCoy wants to examine van Gelder, once a renowned psychiatric doc, now reduced to a barely-coherent, tortured mind. When van Gelder attempts to speak he can only give a few bits of information before bouts with horrible pain anguish him into a physical wreck. McCoy will appeal to Spock to use the ancient Vulcan mind meld technique to probe van Gelder's tormented mind for answers. Meanwhile, Kirk, reluctant but carrying out the duty of his position when McCoy states in his medical log doubts in regards to the techniques used by the distinguished Dr. Tristan Adams (James Gregory; The Manchurian Candidate), transports, with an officer recommended by Bones due to her field in psychiatry, with Dr. Helen Noel (Marianna Hill; High Plains Drifter / Blood Beach) to the penal colony to "investigate" the methods used on the patients. Discovered by Spock and McCoy during the mind meld, a machine is mentioned by van Gelder--Kirk is interested in its effectiveness when he visits it while on his tour and wants Noel to guide him through how it operates, with Adams using it on him because of the threat the Captain poses to his secret misbehavior--describing it as a neural neutralizer. Adams, it is soon realized, is responsible for using the machine to wipe the minds of his patients, replacing his own thoughts and commands, such methods giving him quite the power to influence anyone he so chooses. Kirk will need Noel to shut down the power while Adams forcibly uses the mind sucking machine to further torture the Captain. If the power is shut down, Spock and security can beam down because the penal colony has a forcefield that disrupts transportation.
Woodward certainly convinces as someone mentally enduring some serious pain, showing it on his face and providing the bodily suffering that might result in resisting Adams' control. Gregory puts on quite a face of total collaboration with Kirk in regards to how tip top his operations are, so willing to allow total scrutinized study of his work in the rehabilitation of his patients and the living conditions produced by his treatment. It doesn't come as no surprise that he's actually an evil bastard raping the minds and thoughts of people that fall prey to his dastardly machine (the way it sounds and rotates, and the agonizing cries of those who sit in the chair, this machine is a beast), because Gregory plays him as someone with a smile on his face and a dagger (pun intended) clamped in a fist like grip behind his back ready to stab. The mind meld itself is fascinating to watch: Spock almost seems to be in a state of ecstatic bliss while clutching the surrounding face and forehead of Woodward, who is actually calm and in complete peace while under this Vulcan probe. That final scene where Kirk sits in his Captain's chair, looking at the planet he barely escaped with his sanity intact, his face totally aware of what his mind had just been through, certainly explains a lot of what it might be like to endure such a hardship. The scene where Gregory gets more than a taste of his own medicine, but without the person on the other side providing his own thoughts, totally alone to be mind sucked into his own oblivion, is a fitting end to him for what he done to those under his care.
Woodward certainly convinces as someone mentally enduring some serious pain, showing it on his face and providing the bodily suffering that might result in resisting Adams' control. Gregory puts on quite a face of total collaboration with Kirk in regards to how tip top his operations are, so willing to allow total scrutinized study of his work in the rehabilitation of his patients and the living conditions produced by his treatment. It doesn't come as no surprise that he's actually an evil bastard raping the minds and thoughts of people that fall prey to his dastardly machine (the way it sounds and rotates, and the agonizing cries of those who sit in the chair, this machine is a beast), because Gregory plays him as someone with a smile on his face and a dagger (pun intended) clamped in a fist like grip behind his back ready to stab. The mind meld itself is fascinating to watch: Spock almost seems to be in a state of ecstatic bliss while clutching the surrounding face and forehead of Woodward, who is actually calm and in complete peace while under this Vulcan probe. That final scene where Kirk sits in his Captain's chair, looking at the planet he barely escaped with his sanity intact, his face totally aware of what his mind had just been through, certainly explains a lot of what it might be like to endure such a hardship. The scene where Gregory gets more than a taste of his own medicine, but without the person on the other side providing his own thoughts, totally alone to be mind sucked into his own oblivion, is a fitting end to him for what he done to those under his care.