I like TOS Operation: Annihilate! because it presents a situation where a starship captain would be justified in issuing General Order 24. I’m disappointed that they didn’t actually mention GO24 in the episode, but my headcanon is that the crew were all reluctant to mention it by name.

I think GO24 is deeply misunderstood. It’s only ever been presented as a thing that a bad, crazy captain would order; as grounds for mutiny. So why would Starfleet even have such an order on the books? I think it’s actually designed for situations like the one in this episode: to prevent the spread of dangerous life forms.

This interpretation also enhances my enjoyment of another TOS episode, A Taste of Armageddon. In this episode, Kirk actually invokes General Order 24. Scotty understands that Kirk needs leverage to bluff with, and plays along. Bluffing the bad guys by citing a public health ordinance is classic Kirk. See also Corbomite and Fizzbin