The Enterprise follows an ion trail left by the Brain Burglar. Then they lose it. However, Kirk, he's smart, so he figures that since the trail went into a system called Sigma Draconis, that's a good place to start. He looks at schematics and picks the most likely planet. Well, it's not the "most likely" planet because none of the three Class M planets that possess sapient life is capable -- by Chekov's reports -- of launching interstellar travel. One planet is placed on the industrial scale to be equivalent to Earth in 1485, another is Earth's 2030 (so we know Horatio is defending some guy with three penises there), and the third is in a glacial age with "no sign of industrial dewelopment." What a puzzler! Uhura reports high-energy generation from the glacial planet at regular intervals. Kirk questions Chekov about the life on the planet, and Chekov says, "No sign of organized civilization, primitive humanoids picked up at irregular interwals." Ah, but the energy readings ARE regular, so, my dear Watson, guess where Spock's brain is? It's elementary for Silent E! Who can turn a pan into a pane? Who can turn a man into a mane? Kirk talks to himself, "I can't afford to guess wrong. I've gotta choose the right planet, get there, find the brain [score: Banon]. Eight hours and thirty-five minutes." He asks Chekov and Sulu for their opinions. Nothing comes of that endeavor. Finally Uhura muses, "What would they want with his brain? What would they want with Mr. Spock's brain -- what use is it? Why do they want it?" This gets Kirk thinking. It gets me thinking that the success of this entire mission should be credited to Uhura. Blah blah blah they're going for the glacial planet. It's the least likely, therefore it's the most likely plot device. Chekov wonders what will happen if Kirk guesses wrong. "If I guess wrong, Mr. Chekov, Mr. Spock is dead," Kirk says, and adds for those who can't comprehend the present tense, "Spock will die." Okay, they have a crew complement of what? Four hundred something? Why not send away teams to each planet to look for the brain (hee hee hee) all at the same time? Who ever finds it first comms the ship, the ship comms everyone else, and they put the brain back.