Frankly I'm surprised I haven't discussed this topic already back in the heyday of "Star Trek: Enterprise" optimism. It was prompted as my son and I were watching "Balance of Terror." Early in the story Captain Kirk and the insubordinate Lt. Stiles are at loggerheads. The navigator challenges Kirk with an accusation, reasonable or otherwise, that "We could have Romulan spies aboard this ship." My son, given his personal humor and seeing a new face in Chekov's seat, called out facetiously, "Yeah, you're the spy!"

I didn't take it up with him until after the episode but I'd actually heard that idea before. This highly imaginative and (as far as I know) original theory was advanced by my 3D chess opponent, the chessmaster of the Romulan S'Task University. He argues persuasively that we're actually watching the failed sabotage mission of the deep cover Romulan spy, S'Tiles. (And the strong, dark features of actor Paul Comi only help the suggestion.) The mission of this officer, a reverse "Enterprise Incident" if you will, was to insinuate himself among the Federation craft patrolling the Neutral Zone, instigate dissention and distrust among the crew of that ship, and at all costs ensure that the destruction of the outposts succeeds.

The hints are there throughout the show. He shares intimate knowledge of Romulan designs and strategy (and it's certainly a bit odd Kirk has so little knowledge about this capacity of his bridge officer). Obviously a Romulan would not need much prodding to accuse a Vulcan of disloyalty, and it's a quick-witted move to distract attention from the intercepted message that costs Decius two steps in rank. Near the end Stiles "volunteers" for duty to "help" the overworked phaser crew. Clearly if Spock hadn't overheard Kirk's desperate cries to "Stiles, can't you hear me? Fire!" the Enterprise would quite likely have been blasted by the warbird's plasma weapon.

Against the theory? Stiles does call for a heightened state of security. He couldn't have known they'd survive the atomic blast at point blank range (well, one hundred meters). That blast presumably evacuated Tomlinson's phaser crew, introducing the opportunity for Stiles to join him. And of course this episode appears early in canon, when the Trekverse wasn't quite cooked. All in all it's just a little light-hearted thought (do Romulans have "light hearted thoughts?") to consider the next time you view the show. (And consider that Stiles never appears again!) Still, it's amazing the rich details that peek out at us from episodes we've encountered uncounted times.