Kirk's body weakens more quickly than the others, requiring additional doses of the serum. Henoch tries to tempt Thalassa into keeping their hosts' bodies, because the android forms will be incapable of sensuality. She in turn tries to convince Sargon, but he collapses. McCoy declares that Kirk's body has died and Sargon is gone. Back in sickbay, McCoy is able to revive Kirk's bodily functions, but has no way to restore Kirk's mind. Thalassa offers to restore Kirk in exchange for McCoy's help in keeping Mulhall's body. When McCoy refuses, she assaults him telepathically, but then has a change in heart and relents. The voice of Sargon commends her, and she realizes that Sargon is using the ship itself as a temporary body. She then informs McCoy that Sargon has a plan, and locks him out of the examination room, after which Chapel marches out of sickbay. McCoy reenters the examination room and finds that Kirk and Mulhall have been returned to their bodies. However, the spheres have been destroyed, including the one that held Spock's mind. Kirk says that this was "necessary", and asks McCoy to prepare a lethal hypospray for Henoch. Henoch, who has taken control of the bridge and is terrorizing the crew, reads McCoy's mind and prevents the injection. Henoch then commands Chapel to use the lethal compound on McCoy. She moves as if to comply, but then injects Henoch instead. Henoch boasts that he can transfer to another body, but finds he cannot due to interference from Sargon. Henoch pleads for mercy, but Spock's body collapses, seemingly in death. Sargon tells Kirk that he could not allow this. Spock's and Chapel's bodies glow, and Spock revives. Sargon reveals that the injection was not lethal; it was important for McCoy and Chapel to believe it was lethal so that Henoch would believe it also. Spock's mind had been temporarily placed in Chapel's body. Sargon and Thalassa announce that they will not attempt to build host bodies, but will "depart into oblivion" instead. They make a final request, which is granted: to be allowed to use Kirk and Mulhall's bodies one last time to share a kiss. Reception Michelle Erica Green of Trek Today writes that the story is "an entertaining and engaging episode about power, loyalty and the struggle between physical and mental pleasures... and because there's an alien in his body, Spock spends a lot