"By Any Other Name" this episode would still reek of mediocrity. It's slow paced if not outright dull with no action and as few thrills. The guest actors are supposed to be pale lifeless things so they can't really be blamed (note the subtle job in makeup from pasty white to ruddy as the Kelvans "humanize"), but except for two scenes even the majors are incapable of placing pleasant fragrance on this bloom. Internal references to other TOS episodes are rare, yet here we get two that add nothing to the plot. How D.C. Fontana and Jerome Bixby allowed this clutch of clichés to escape remains a mystery.

The Kelvans may be the closest TOS comes to a Borg-type alien, an unstoppable, unflappable threat determined to conquer humanity. That they are so inept at their task belies their reputation as galaxy hopping, power mad conquerors. Why their Empire would opt to planet-shop two and a half million light-years and several centuries away is not explained, neither their stupid strategy returning all the way back (instead of probots allowing the conquest to continue). Where did the Kelvans come up with human bodies to occupy anyway and how does such hosting operate? To allay rebellion why not compress and rehydrate "specialists" only should their advice become necessary? This is B-grade stuff!

Other complaints include strange production details like that thunderbolt sound effect when Spock breaks his mind touch, or the need to keep humans behind bars instead of simply frozen (when that power has already been demonstrated). The "jailed" situation does allow a "jailbreak" which is used to introduce the Kelvan cube collapse and subsequent crushing of Thompson, one of the more unexpected and cold-blooded killings in the show. (Kudos to Kirk here though for convincingly expressing his anguish over poor redshirt Thompson.)

It's certainly not all bad. Warren Stevens and Barbara Bouchet handle the roles of Rojan and Kelinda cool, capably, full of lackluster kisses. Spock is hilarious falling asleep as he trustingly falls into the arms of his friends. And certainly one of the most memorable scenes in all of Trek is the indescribably funny drinking sequence between Scotty and Tomar (superbly acted by Jimmy Doohan and Richard Fortier), in need of something to "wash down" a hearty meal of colored edible cubes. This encounter, our only visit to the engineer's quarters (suitably equipped with bagpipes and kilt and a very, very old bottle of scotch - whiskey!), features that classic sobriety-defying description known to all true Trekkers: "It's green."