"The Doomsday Machine" excels in action and acting. Confronted by a giant weapon of great power, one capable of destroying entire worlds and certainly puny starships, Kirk must prevent the imminent destruction of his vessel and crew. Confounding the matter is Matt Decker, the devastated, demoralized captain of the wrecked sister ship Constellation, determined to avenge the loss of his crew even at the cost of Kirk's. Their dedication however, to their captain and to each other, manifests itself in their deft handling of the emergency. Kirk is furious to insubordination at a superior officer for jeopardizing his ship, as a mercilessly logical Spock outthinks Decker (no slouch at quoting regulations) to retrieve command of Enterprise. Vulcans never bluff indeed! And Scotty really "earns his pay for the week" having the presence of mind to recharge the phaser bank that distracts the planet killer leading to their eventual salvation.

The fantastic William Windom presents an unparalleled guest performance as the mad Commodore Decker. Even as he usurps the bridge for his suicidal to exhort futile revenge against the planet killer it's hard to completely dislike him (though tossing McCoy off the bridge? How rude!). Faced with losing his first command he made a terrible mistake and paid for it ultimately with unfathomable loss. His curt "Don't you think I know that?" drips with the pain he feels for those lost under his command. No doubt at his best he was an admirable, competent commander (under extraordinary strain he clobbers a guard and steals a shuttle out from under Sulu) but truth be told, considering the inspiration drawn from his "suicide" it appears we were better off without him.

Then there's the "other" guest star, the unstoppable silent but deadly planet killer. The author's description of a device bristling with weapons was constrained by special effects budget and technology into a magnificently mysterious yet intimidating sleek appearance. (The seams appear when smaller crafts are shown oversized in the enormous maw of the machine.) Sol Kaplan's memorable soundtrack enhances this Hugo-nominated effort almost beyond criticism. Almost. Early on Decker describes observing the weapon "slicing out chunks" of the fourth planet, demonstrating a degree of incompetence to send his crew planetside. And since life support systems were operable in Constellation, wouldn't someone insist on staying with the captain? It's such a favorite though, several excellent efforts attempted to rework the material even before enhanced TOS did. For as much trouble as the device was, we could use more top quality episodes like this.