Alan Dean Foster's 1975 Star Trek Log Five contains 3 stories adapted by Foster from the screenplays of the early 1970s animated cartoon television series that had been spun off from the original acted series of half a dozen years earlier.
Never having seen the animated series, I can make no comparison between the original episodes and Foster's adaptations, in the way I occasionally have with James Blish's adaptations of the original series. I can comment, though, that the cartoon series evinces some differences from the acted series. Here, for example, we have a handy piece of technology called a "life-support belt," which creates a very thin but tough force field, meaning that characters can stomp around in vacuum or poisonous atmospheres as if in a spacesuit. And of course another product of the animated nature of the show is that we have a few alien crew members--three-legged and three-armed, cat-like, or winged, for example--who would have been too expensive to produce every week via elaborate costuming, along with other odd aliens occasionally encountered. These differences are commonsensical, at least in science fiction, and they do not draw attention to themselves unduly.
In "The Ambergris Element," whose original screenplay was by Margaret Armen, the Enterprise must scout out a planet called Argo, which "until quite recently (according to drone probe analysis) had been largely a landed planet" but whose surface now is "ninety-seven percent water" (1979 Del Rey paperback, page 12). Apparently "[t]his world had been subject to a series of evenly spaced seismic convulsions--intense without being cataclysmic--in a very brief period of time" (pages 12-13).
With "at least one other, well-populated world in the Federation" that might be in similar seismic danger, potential "techniques for dealing with such subsidings on a selective basis ha[ve] been developed, but only in theory," so an uninhabited planet is needed for such "experimentation with the planetary crust" (page 13). Since "the regs say that any world holding life larger than a bacterium requires at least one hands-on survey by a visiting ship"--especially justified here, considering "how much trouble drone probes have getting accurate data on the life of water planets"--Kirk, Spock, McCoy, and a pilot go down in a shuttlecraft special-built for underwater work (page 15). And there, in collecting specimens and encountering, essentially, sea monsters, the Captain and First Officer encounter a problem that will require diplomacy, medical science, and underwater fisticuffs to resolve...
"The Pirates of Orion," whose original screenplay was by Howard Weinstein, has Spock in medical danger once again. This time the peril is "[c]horiocytosis," "a strange disease" that is "relatively simple to handle in races with iron-based blood." Yet while it is merely "a nuisance to humans," with Vulcans it has a "[n]inety-three percent probability" of death (page 85). There indeed is a drug, "strobolin," that "would certainly improve the odds in Spock's favor astronomically," but the medicine in rare, and somehow even "nobody's been able to synthesize it," even after "[s]ixty years in the lab" (page 86).
The nearest source of strobolin is too far away, even "at maximum warp," reports the computer (page 87), to reach in time, but if a cargo ship from carries the drug from that planet to a rendezvous with the starship (page 88), then Spock just might be saved. But if that freighter, which also happens to be carrying valuable dilithium crystals (page 92), finds itself being intercepted in deep space by a vessel of unknown design, and "colored blood red, a choice which might be coincidental, theatrical, or intentional" (page 95)...well, then we clearly have a problem.
In "Jihad," whose original screenplay was by Stephan Kandel, "a Class-A Security Prime Order," meaning one whose "classification [is] so strict that Kirk [is] required to unscramble it himself, using a locked computer annex, in the sanctuary of his own cabin" (page 135), diverts the ship to a mysterious rendezvous with one of the "large asteroids or small planetoids which have been remade to suit [the] environmental requirements" of "[t]he Vedala," who "are the oldest space-traversing race known. They are so old that they long ago abandoned their worn-out home worlds to begin a nomadic life among the stars" (page 137).
The Vedala are, as they admit, "extremely protective of [their] privacy" (page 138), and Kirk notes that they "are known to possess certain technological abilities beyond the combined talents of our Federation and other governments" (page 146). Despite this latter, however, they themselves cannot undertake the quest for a religious object whose recovery can forestall a catastrophic war that otherwise would gut the galaxy (page 144-45), so Kirk and Spock and a team of specialists from entertainingly varied alien species must go, for some reason with almost no technology, to a "mad world" (page 146), or "globe [that] is a compendium of catastrophes" due to "radical seismic activity and unpredictable tremors. A most inimical climate. Severe tidal disturbances caused by unceasing action of five moons possessed of the most perverse orbits--the list is endless" (page 147). This one is just a bit cartoonish in its semi-low-tech slog across deserts and ice and quick-appearing volcanoes, but it's fast-aced enough to keep our minds most off that.
In any event, Alan Dean Foster's Star Trek Log Five may begin with stories originally from a cartoon show, yet the adaptations are well done and aimed at an adult audience, and for any fan of the starship Enterprise and its historic five-year mission, the book will be a swift and enjoyable 4.5- to 5-star read.