Why does the eel in Chekov’s head leave after Terrell’s death?
Don’t get me wrong: I’m glad the Ceti eel inside Chekov’s cranium decided to vacate it! I’ve never wished death for the character, and especially not as the psychically-controlled puppet of a madman. And the Ceti eel’s exit from Chekov’s ear still ranks as one of the most viscerally disgusting moments in any Star Trek movie. (Such moments are, when you think about it, thankfully few and far between.)
But why does Chekov’s eel choose to vamoose as soon as Captain Terrell has turned his phaser on himself? The sequence of events makes no sense unless we posit some connection between the eels inside the two men. Maybe the one eel senses the destruction of the other, knows the jig is up, and tries to get while the getting is good?
When he turned his “pets” on Terrell and Chekov back on Ceti Alpha V, Khan said they rendered their victims “extremely susceptible to suggestion.” He said nothing about any effect the eels might have on each other.
Or should we give Chekov credit for freeing himself from his eel’s influence? Much as I’d like to think Pavel mustered up the strength of mind and will to force his eel out, the way Walter Koenig plays the scene simply doesn’t support that interpretation. He raises his right hand to his ear swiftly, as though surprised, and his face has an expression of sudden terror, not intense concentration.
It’s a convenient moment for Chekov’s eel to give up control over him, and it gives us an emotionally satisfying beat as Kirk burns the beastie to a crisp with his phaser (no matter what Gene Roddenberry thought of the scene). But it makes little logical sense.