McCoy Becomes Paranoid (The City on the Edge of Forever)

On stardate 3134.0, the Federation Starship U.S.S. Enterprise investigates temporal disturbances centered on a nearby planet. During the investigation, Sulu is caught in a console explosion and suffers a heart flutter. Doctor McCoy is summoned to his aid and decides on a cordrazine shot to awaken him. Moments later, McCoy accidentally injects himself with an overdose of serum causing him to become violently paranoid. Delusional, McCoy flees from the bridge and beams down to the planet.