Terrence Dicks is how a lot of Americans know about "Doctor Who", as he wrote most of the novelisations of the TV serials (that was how I first discovered the show, or at least became familiar with it) . . . and while his writing style in those books worked just fine to convey what was on screen in a prose form, it lacked a certain amount of flair overall, something that became obvious when the Virgin New Adventures came around. Dicks' few novels for that line were passable, entertaining but seemingly out of place with the other writers' more considerable verve and insistence on breaking new ground (sometimes doing that instead of telling a story but that's a debate for another time). In that context he seemed like one of the Old Guard, while they were trying to push the series in a new direction.
This only got worse when he inaugurated the BBC line of adventures featuring the Eighth Doctor, as his first novel for that was just godawful, a string of "This happened and this happened and this happened and then the story was over" that wasn't even that entertaining. The saving grace was that it read quickly. So now he comes along again with a novel featuring Jon Pertwee's Doctor, a era of the series he's probably vastly more familiar with. And the difference shows.
The Doctor and Jo Grant, alerted by a psychic distress signal, land on a colony world where the passive native giants are used as slaves by the current landholders. But strange things are starting to happen, as the giants are randomly starting to become violent, smugglers are combing the planet for a local native drug, and every dogooder for parsecs is arriving to further their own cause. The Doctor gets mixed up in things and as usual has to figure out what's going on while everyone is either trying to recruit or arrest him (and sometimes both at the same time).
The novel is impressively readable and while it's not pulse-pounding or emotional, it's highly professional, doing what it has to do to keep the story moving. The main military and administration people are shown to be well rounded and even reasonable, which keeps the situations humorous at times and distracts you from the fact that the story boils down to the Doctor getting captured and escaping and getting recaptured several times, with only mild variations. Like I said, Dicks is able to do this well enough so that the story remains entertaining without being repetitious, but at the same time it points out that the plot isn't really that complex.
As a side bonus, the rather underused Draconians show up and while Dicks doesn't seem to be sure if they are supposed to be comedy figures or taken seriously, it's a nice call-out to a memorable alien race from those years of the show, even if they don't do all that much and seem to be there merely to allow the plot a neater wrap-up (or needlessly complicate things).
You'll read it, you'll probably enjoy it and it will only take you a few hours, at which point you'll rarely think about it again. This literally could have been a TV episode, and does a good job of evoking the era. So if you want a dose of nice comfortable "Doctor Who" then this is probably exactly what you're looking for.