"The Window" - After mysteriously collapsing in the corridor, Spock is taken to sickbay where a brain scan leads McCoy to discover Spock has suffered a brain aneurysm. Following an emergency brain surgery, Spock is sent back to Vulcan to recover, and stay with Amanda and Sarek, who both have totally opposite reactions to the situation; Amanda is thrilled to have Spock home, but Sarek refuses to speak to Spock. Spock suddenly begins to exhibit emotions, and while Sarek shows disapproval, Amanda encourages Spock to experiment with his feelings. Finally, things come to a head when Sarek demands Spock mind meld with him, which leads to Spock refusing and running away. Spock manages to reach The Window - a Vulcan holy place where Vulcans first started practicing total logic, so named for the nearly bottomless chasm in the middle of the ground - when Sarek finally catches up, and grabs Spock from behind in an attempt to mind meld with him. Spock and his father struggle until they both fall into the chasm. Spock suddenly awakes, once more on the Enterprise and in Sickbay, and it is revealed that Sarek had been called in to revive Spock via mind meld after he had collapsed in the corridor. Everything Spock had experienced since the fall had been a manifestation of his human and Vulcan halves subconsciously battling for dominance, with Sarek's mind meld tipping the balance in favor of Spock's Vulcan half. Spock reports to the bridge, after a short conversation with Sarek about the importance of logic, and only after the two are out of earshot does McCoy roll his eyes and say, "Like father, like son."
Next episode: "Fell Deeds Awake" (The Lord of the Rings: Return of the King, Chapter 5 "The Ride of the Rohirrim")