That observation of Science Officer Spock by Commodore Mendez (Malachi Throne) is at the core of the brilliance of this episode. Earlier stories in the series may have been good, but this was the first great one. It's well detailed and highly suspenseful, with a mystery that makes the viewer highly anticipate the resolution to Spock's behavior. The writing also solidifies the dual nature of Spock's heredity. As part Vulcan he's incapable of lying, as half human, one must consider whether that part of his make up is prone to treachery and treason. Besides all of that, you also have the intrigue of Talos IV, and why Fleet Command would impose a death sentence for any of it's members to venture to that planet. All very 'fascinating' as Spock himself might be prone to describe it if he wasn't so busy manipulating the ship records on the Enterprise to cover for his subterfuge. With still more to come, the general court martial convened for Spock would have given Captain Kirk the perfect opportunity to use a line that us fans had to wait for, for four decades until the release of the 2009 movie - "Are you out of your Vulcan mind"?
Review of The Menagerie: Part I
