In Gold Key issue 4, “The Peril of Planet Quick Change” (June 1969), Spock discovers a highly unstable planet in “Galaxy Telpha Z.” The constantly shifting surface is dangerous, but Spock has also detected tiantianium ore, “an ounce of which can propel a spaceship for a year,” as Kirk says, so a landing party is quickly assembled.
After a surface upheaval exposes ruins of an ancient civilization, the landing party is buzzed by strange blobs of light, which eventually focus on Spock before apparently dissipating. Shortly afterward, while still searching for the ore, there’s another transformation of the surface, and water gushes into the desert. Spock, who happens to be standing on an outcropping above the water, throws Kirk a rope, telling the captain to “instruct the others to make a life-chain of their bodies by clutching yours.” So instead of McCoy and the other crewman each holding the rope and carrying their own weight, they both grab onto the man above, leaving Kirk’s grip on the rope supporting the combined weight of all three of them!
Spock single-handedly pulls them all up, which Kirk finds odd, so apparently the author wasn’t aware that Vulcans are far stronger than humans. But next Spock really does start behaving strangely, barking out orders for the construction of a rocket to deliver a payload to the planet’s core to stop its constant metamorphoses. He has supplies beamed down from the Enterprise, including two huge trucks that would look at home in an episode of Thunderbirds.
Spock becomes aware that the light blobs didn’t dissipate, they entered his mind; they are the ancient inhabitants of the planet rendered incorporeal by chemical reactions caused by a meteorite impact “many sun centuries ago” (continuing the Gold Key trend of adding an astronomical term in front of a unit of measurement to sound futuristic). They are controlling him in order to repair the planet. After further high jinks, the rocket delivers its payload, the planet stabilizes, and the previous civilization is once again rendered physical, including the people who had kinda sorta possessed Spock. Well, five of them. A sixth attempts to stay in Spock so that he can travel the galaxy, (shades of the second season episode “Return to Tomorrow” and other possession-type stories across all the series) leaving Spock ill and stumbling around.
Strangely, although the rest of the landing party witnessed the five lights exiting Spock, none of them suspect the possibility that he’s still possessed by another of them even while he mutters things like “Inside of me…something!” Luckily, Spock is able to exorcise his unwelcome guest by using the transporter to disrupt the being’s hold on his body. Although this causes the being’s death, the rest of the planet has been saved, and the landing party procured “two hundred galaxy pounds” of rare tiantianium. The issue ends with an exchange between McCoy and Spock that captures two classic motifs of the original series: a humorous coda and the Doctor and the Vulcan teasing one another. All in all, a pretty good Trek story.
Favorite exclamation: Kirk’s “Great galloping galaxies!”