These four K-9 children's books were included as PDFs on the DVD release of The Invisible Enemy/K-9 & Company. I decided to count them all as one review because they are so short. (Of course I might change my mind on that if I come up 3 reviews short in December...)
The Adventures of K-9 #1: K-9 and the Time Trap by David Martin. PDF, 36 pages, Sparrow Books, orig. pub. 1980.
K-9 is dispatched on a mission to find the Rigelian Seventh Fleet, which is one of a number of "vanishments". He travels in a K-NEL!
*Warning: SPOILERS* First off, how on earth was he able to carry that battle cruiser with just a magentic pad? On the other hand, the writing was very K-9. "Fear has not been built into my circuitry." Just as I'd expect from one of the co-creators of K-9. Omegon -- this seems to be a reference to Omega both by name and by situation, but I haven't seen the Omega story (stories?), so I don't have a frame of reference for that yet. He sacrifices his K-NEL to save Gallifrey! But then he gets a new one! "Stripes... are not improvements."
The Adventures of K-9 #2: K-9 and the Beasts of Vega by David Martin. PDF, 36 pages, Sparrow Books, orig. pub. 1980.
K-9 travels to Vega 3 to investigate a strange disorder striking down space workers.
*Warning: SPOILERS* So the Professor is female but ALL of the crew of ALL of the spaceships are male? Not buying that. There's one illustration that makes her look like she's wearing an opaque greenish sweater over a strapless bra that keeps making me go WTF? The interlocking planet creation was cool, as was the idea of the psychological monsters. On the other hand, I thought the ending "when you explain things, they'll magically get better" was a bit of a cop-out. Oh, and lol Vegans!
The Adventures of K-9 #3: K-9 and the Zeta Rescue by David Martin. PDF, 36 pages, Sparrow Books, orig. pub. 1980.
K-9 must answer a distress signal in Zeta Four Sector, where a star possibly going Nova is too hot for even the Time Lords to handle.
*Warning: SPOILERS* The artist for this book surely didn't know what a Time Lord was supposed to look like, to judge from page nine. This book reads almost like it's meant to be first or second instead of third in the series, but the new K-NEL design and the numbering would suggest otherwise. The sections with K-9's thoughts were interesting. The Megellan empire -- are they featured somewhere else? One of the disadvantages of being so new to Who is that a lot of these references fly right over my head.
K-9 gets a sidekick! Turns out she's the one-adventure only type though. (The K-9 fandom's Sara Kingdom?) The conversation with the space controller was interesting, and I liked the ending of this one. Very like K-9 to find a logical reason for doing an illogical thing.
The Adventures of K-9 #4: K-9 and the Missing Planet by David Martin. PDF, 36 pages, Sparrow Books, orig. pub. 1980.
Tellus, formerly known as Earth, has lost a planet and they want it back. That was a very valuable planet. Oh, and if K-9 wants he can rescue the humans who were lost on it too.
*Warning: SPOILERS* Yet another time-warping story. This 36-page-each series is already repeating itself on the fourth book, no wonder it didn't continue any farther. K-9 gets to go to another universe and travel through the first 500 million years of evolution, thanks to Star Crystal. Once again he decides to do something somewhat against his programming and mislead the Time Lords, but for a benevolent cause. Writing-wise, I did notice that he flies into a transparent dome that opens to let his K-NEL in, but the only modern technology is supposedly a hot air ballon.
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I read them using the Two-Up (Show Cover Page During Two-Up) display function so that the text pages would display next to the pictures as they presumably did in the original. (For those of you not familiar with this series, a typical two-page spread has a few paragraphs of text opposite a very '80s full-page color illustration.)
Each book begins with the same brief overview of K-9's "Most Secret" file as sent to Gallifrey High Command. This lays out the central idea for the series: K-9, as modified by Time Lord Theta Sigma (is that canon?), will be sent on missions deemed too dangerous for the Time Lords to interfere. This doesn't entirely make sense, since the Time Lords are mostly immortal, so they presumably wouldn't find some of these "dangers" much of a problem.
The illustrations on some of these were pretty bad, like the one on p. 19 of Beasts of Vega, where an ailing crewman looks like he's giving the thumbs-up sign. That picture also has the same crew member's suit depressurizing from the front of his suit, when the text clearly states that he depressurized from his helmet.
I think that had these been modern books I would have been much harsher on them, but given their age, I'm going to give them an "enjoyable" rating. They were quick reads and amusing even if I wouldn't quite count them as canon. Not terribly collectible save for die-hard K-9 fans, but if you get them on the disc anyway, you might as well read them. Some of the lines were quite humorous (whether intentionally or not) and overall it was a nice nostalgic 80s trip.