While held in captivity by the Eymorgs, James T. Kirk, Leonard McCoy, and Montgomery Scott were tortured by pain bands several times. Drawing upon Spock's interface with the knowledge of the builders, Kirk discovered that a red button released the belts. Spock's body, at that time lacking its brain, was not subject to pain, so Kirk was able to operate it by remote control, causing it to seize the bracelet on Kara's wrist and then to then press the necessary button, releasing the bands.