If 1972 had a torrent of James Blish's adaptations (four!), 1973 had a drought. In August 1973 was published that year's sole entry in the series, Star Trek 9. This volume adapts "Return to Tomorrow", "The Ultimate Computer", "That Which Survives", "Obsession", "The Return of the Archons", and "The Immunity Syndrome".
In Return to Tomorrow, the Enterprise encounters three aliens, survivors of an ancient war, who wish to borrow a few of their bodies to build android bodies for themselves. This adaptation isn't bad, but it's really another story that got most of its value from seeing the characters acting unlike themselves, which works much better on television. Reading of the doings of 'Sargon-Kirk' just isn't the same as watching William Shatner, after all.
In The Ultimate Computer, Dr. Richard Daystrom, the brilliant scientist who built the Enterprise's computer, has invented a new kind of computer, the M-5 multitronic unit, which promises to be so capable as to replace a starship's entire crew, and the Enterprise has been given the honor of testing it. When the computer malfunctions, it's up to the skeleton crew that remains on the Enterprise to regain control of their vessel before their comrades in Starfleet are forced to destroy them. An entertaining story.
In That Which Survives, the Enterprise and a landing party are attacked by the image of a woman, who is actually a computer-controlled replica defending a dead planet. A threadbare story, indeed. We're meant to feel some sympathy for the woman, and it works a little in the TV episode, but I just don't feel it in the short story. Forgettable.
In Obsession, the Enterprise encounters a murderous cloud creature that, eleven years ago, killed many members of the crew of the Farragut, on which Kirk served as a lieutenant. As they investigate, the clock is ticking, since the Enterprise must rendezvous with the Yorktown to transport some highly perishable and desperately needed medical supplies. This story works out far too well for Kirk--he clearly is simply obsessed (as the title indicates) with the creature, and his decision to put off meeting up with the Yorktown is clearly a dangerous one, but since he's friends with the writers it turns out he was right all along. I'm not a fan of this one.
The Return of the Archons tells the story of yet another society made stagnant by a ruling godlike computer, Landru. And once again Kirk convinces it to kill itself. A fairly entertaining story. I'd like to get some more information on the creation of the computer, its original purpose, whether it was immediately tyrannical or became thus over time, but there's never enough time in an episode for much detail, and these adaptations aren't any different. It's still worth a read, though.
In The Immunity Syndrome, the Enterprise encounters a giant space amoeba. Which they blow up. The end.
Star Trek 9 is another middling entry in Blish's series of adaptations. A few of the stores are reasonably entertaining, but "That Which Survives" and "The Immunity Syndrome" are rather dull. I admit that at this point I'm really looking forward to the end of this series. Fortunately, there's just one more to go before Alan Dean Foster's Star Trek Log series begins, and then a couple more later on. I can stick with it that far. My advice for this one is just as usual: only get it if you particularly liked one of the episodes adapted in this volume.