"The Immunity Syndrome" represents iconic Trek as no other episode quite does. This may not only be the quintessential "bottle story" (set entirely inside the ship, yet still exploring the "unknown") but would certainly vie for most visually magnificent as well. Despite the strange science behind a planet sized amoeba, or the intense fluid pressures a starship would experience on such a fantastic voyage, despite legitimate questions about its origins and potential successors, the stark beauty of NCC-1701 with or without the psychedelic matte acts efficaciously as an-ti-body to disbelief. The Emmy-nominated Van Der Veer visual effects are so spectacular they stand up to contemporary CGI expectations, and more than compensate for the tracked musical segments that compose the score (even though such segments are well employed).

Rarely do we see these heroes operate both individually and collectively against imminent danger. (And all this in their exhausted, shore-leave depleted state.) Once again Kirk proves himself the best decider in his torments about selecting which of his best friends is better qualified to die. Rarely also do we see Kirk so peripatetic, going back and forth from bridge to quarters and back again as precious minutes pass (too bad this episode wasn't directed in actual time to enhance the thrill). Undoubtedly succeeding where the Intrepid failed immeasurably improves Kirk's reputation amongst the undoubtedly astonished Vulcans.

There's little here to disparage, only a few oddities to the purists. Kyle seems strange in his gold uniform, and that incongruous "bloody history" interplay between Spock and McCoy goes nowhere. That banter however flows nicely with the rivalry that continues throughout the episode, and there's more than a few selections to add to Trek's memorable quotes ("Are you trying to be funny Mr. Spock?" and "Thank you, Captain McCoy"). The Big Three are in excellent form here, drawing strength from each other, yet the supporting cast (plus many new non-speaking faces) gets involved also with especially great screen time for Scotty, Chekov and Uhura (including her chair-tipping upset on the bridge!).

The episode bookends with hints to the demands that starship patrol places on the health of the crew. Still including this factor they manage to save the day. This is indeed the finest ship in the fleet (even by Vulcan standards!). The expressed goal of their mission is to "seek out new life" yet it's safe to assume this sort of extreme encounter isn't what they had in mind. But of course for the sake of the galaxy, it's a good thing they did.