Spock/Starfleet/V'ger crisis

Two and half years after leaving Starfleet, Spock felt the arrival of a vast consciousness. He aborted his kolinahr training and resumed his Starfleet career both for personal reasons and to help Rear Admiral Kirk during the V'ger incident. Spock's return to Starfleet amazed former colleagues and others but his reputation remained excellent, with Commander Will Decker stating that he was "well-aware of Mr. Spock's qualifications" when Spock offered to again serve as science officer. Within three hours, he helped Scott repair the Enterprises malfunctioning warp drive. ()
Spock's attitude towards his colleagues was far different from when he had served with them during the five-year mission. Wishing to rid himself of any personal attachments to Starfleet, he no longer considered any of the crew to be his friends and barely acknowledged them upon his return except where his duties demanded it. Feeling that the consciousness would answer for his quest, he broke into an airlock and stole a thruster suit. He exited the ship and proceeded to the next chamber of the mechanism, witnessing a planet populated by living machines. There, he attempted a mind meld and he realized V'gers quest. Knocked unconscious by the enormous power of V'ger during the meld, Spock was recovered in open space by Kirk. Later, he was in sickbay being treated for neurological trauma. He informed Kirk that V'ger was a life-form of its own, seeking answers to its questions; specifically "Is this all that I am? Is there nothing more?" Grasping Kirk's hand while lying on a biobed, Spock told Kirk that the simple feeling of touching another was something beyond V'gers comprehension. 
Spock later accompanied Kirk, Decker, and McCoy to the heart of V'ger, guided by the Ilia probe. The group discovered V'ger was actually the 20th century NASA probe Voyager 6. Spock deduced that the old probe was found by the living machine inhabitants of a planet located on the other side of the galaxy and they built the mammoth vessel so it could fulfill Voyagers simple programming, "learn all that is learnable." Spock told Kirk that V'ger had to evolve, as its knowledge had reached the limits of the known universe. 
Spock informed McCoy and the others that other dimensions and higher levels of being could not be proven logically and V'ger was therefore incapable of believing in them, needing the Human quality to leap beyond logic. Decker chose to merge with V'ger, and Kirk, McCoy, and Spock escaped shortly thereafter when it and Decker evolved into another dimension. Afterwards, Spock chose to remain on the Enterprise rather than return to his homeworld.
Spock's direct encounter with V'ger showed him that purging his emotions and operating on pure logic would not answer his questions but would simply create new ones. ()