This volume adapts the first three episodes of Star Trek: The Animated Series, "Beyond the Farthest Star", "Yesteryear", and "One of Our Planets Is Missing".
Like Blish's Star Trek series, Foster's Star Trek Log series adapts television episodes. There, though, the similarities end. Blish adapted hour-long episodes into roughly twenty-five page short stories. Foster adapts half-hour episodes into (in this book) roughly sixty-page short stories. And oh, but the extra pages are well-used.
I hate to be too hard on Blish, but reading his adaptations is very like reading scripts re-arranged as prose. Plenty of dialogue, some stage directions, and a bit of description to set the scene. But unless Kirk says it out loud, we have no idea what he's thinking, and twenty-five pages is too short for the narrator to spend any time musing on events, either.
By contrast, Foster adapts much shorter episodes into much longer stories, so he can take time to comment and expand on events, to give things some flavor, and to let us know how the characters are affected. It's interesting and, after reading ten volumes of Blish's spartan prose, refreshing.
Beyond the Farthest Star
The Enterprise is en route to the Time Planet, home of the Guardian of Forever from the TOS episode "The City on the Edge of Forever", when they are irresistibly pulled off course. Arriving at the source of the incredible force which drew them in, and (only just barely) managing to enter into orbit about it, they find a 'negative star-mass', or, as Kirk puts it, 'an immensely powerful aggregation of nothing'.
The Enterprise is not alone. They find there a ship of alien design and of extremely ancient origin–some three hundred million years past. Exploring it, they find that the ship discovered trapped in the gravity well of the star a powerful and malevolent alien being. Rather than loose it on the galaxy, they destroyed themselves, depriving it of the use of their ship.
This very being is accidentally transported back to the Enterprise when the away team returns, and quickly infects the ship's computer. Only through guile and sheer nerve are the Enterprise crew able to regain control of their ship and escape both the energy being and the dead star.
Even if 'the Enterprise encounters an unexpected spatial anomaly' isn't the most original plot, this story is still satisfying. It starts off strong, with interesting prose making good use of the opportunity to expand on Kirk's thoughts in a moment of down time. The segment in which the away team investigates the alien vessel, too, is good, giving a nice sense of exploration.
The actual conflict with the alien being I found to be less interesting. The role of the being was mostly to shout commands menacingly while occasionally providing some direct physical danger, and Kirk (in, it must be said, an appropriately Kirk-like fashion) tricks it into leaving the ship just as they escape. There would have been more tension if we couldn't be sure that things would work out in the end, but as the story approached its climax there were still a hundred pages in my right hand arguing against anything too unexpected happening.
Yesteryear
Having finally reached the Time Planet, Kirk and Spock accompany a historian into the past for research purposes. Upon returning, however, they find that no one recognizes Spock–and the Enterprise has a new first officer, an Andorian named Thelan.
It transpires that Kirk and Spock have arrived in a timeline in which Spock was killed by a wild animal at a young age. In the timeline from which they came, Spock was rescued from the attack by a visiting relative. Somehow, this event was prevented while Kirk and Spock were visiting the past.
They conclude that the visiting relative must have been Spock himself, traveling back in time. Other historians viewed Vulcan's past while Kirk and Spock were away. Since Spock was already somewhere else and couldn't exist in two places at once, the past was changed so that Spock's fateful visit never occurred. In order to restore history to its familiar form, Spock must travel into his own past and save his younger self, duplicating the events he remembers as exactly as he can manage.
Despite some minor difficulty interacting with his parents, Spock is successful in preventing his younger counterpart from being killed. However, the le-matya's attack claims another victim: Spock's beloved pet sehlat. When Spock returns and informs Kirk of his success, and the small deviation in the timeline, Kirk opines that "that wouldn't mean much in the course of time", though Spock, affected by the death, replies that "it might […] to some".
This is an excellent story. The episode that it is based on was Dorothy Fontana's sole contribution to The Animated Series, and a worthy contribution it was. It's very satisfying to see a young Spock, to meet his parents once again, to get another glimpse of the planet Vulcan. The story hangs together very well and maintains interest throughout.
One of Our Planets is Missing
"Precisely two and a quarter ship-days after leaving the Time Planet the crew of the Enterprise received a general emergency call."
A very massive cosmic cloud is moving toward inhabited space, and the Enterprise is sent to assess the situation. Before their eyes, the cloud consumes an entire–thankfully uninhabited–planet, Alondra. From there, it proceeds toward that planet's neighbour, the decidedly inhabited Mantilles. It is up to the Enterprise to find a way to stop the cloud before Mantilles's eighty-two million people are reduced to so much stardust, along with their planet. But how can something so massive be stopped?
The Enterprise, swallowed up by the cloud, is given a first-hand look at its interior. To their shock, the cloud seems to be a living being. McCoy recognizes in the cloud's destruction of the remaining fragments of Alondra a similarity to the action of a stomach, and they later find something resembling brain activity.
If they were to target the center of this brain activity and cause the ship to self-destruct, the force would be sufficient to kill the cloud creature–trading its life, and their few hundred lives, for the millions on Mantilles.
As they draw near the critical time, they try a last alternative–at Kirk's suggestion, Spock attempts to contact the creature mentally. As the Enterprise is located inside the creature's 'brain', its thoughts are literally all around them. They route the sensor data through the universal translator, and with Spock as a sort of transmitter, they are able to contact the creature. Just in time, they convince the creature, which has no desire to kill, to leave inhabited space and return to its place of origin.
This story is the weakest of the three. The idea of such a massive and alien creature could be interesting, but it isn't really explored, and the drama is primarily caused by the ticking clock. The best single part, in my opinion, is the brief segment in which Kirk and Scott refill the ship's antimatter tanks. That's not to say that this is really a bad story–it's quite readable, just a bit of a letdown after "Yesteryear".
Conclusion
A digression, here, on the subject of The Animated Series.
In my experience, TAS has not got a very good reputation–which is perhaps a recent development, as it was fairly well received when originally aired. I can understand some reasons why: like TOS, the stories can be far less serious than those told in later Trek, and it suffered from some very subpar animation, from time to time.
For the first point, however, TAS is, after all, intended as a direct followup to TOS–essentially a fourth season. That it has a similar style is no flaw. As to the second: putting aside quality, the use of animation allowed the Enterprise to have regular alien crew members (other than Spock, of course) and to accomplish any desired effects without blowing a whole season's budget. If you ask me, it's better to suffer some low-quality animation than the sameness in a Federation crew.
Back to the book, then.
One thing to note about these adaptations is that Foster ties the stories together chronologically. The first story begins as they are on their way to the Time Planet, the second takes place there, and the third begins two days after they leave. It doesn't really impact the plot–a few minor references to the previous events aside–but it does provide a good sense of continuity. Here, it feels like the Enterprise really is out and about, encountering danger after danger, where in the television series the events felt much more isolated. It's a nice touch.
Star Trek Log One is a worthwhile read, particularly if you find the animation in The Animated Series offputting. No need to miss out on good stories on account of poor presentation! "Yesteryear" is a great character-focused story, bookended by two rather average adventures. All three are quite readable, though, and the book is worth it for "Yesteryear" alone.