There are two Derkholm books! The first one is The Dark Lord of Derkholm, which is mostly a parody of high fantasy novels. It’s not a mean parody, though, or a lazy one (as if DWJ could be lazy, anyway!). It’s something along the lines of a Galaxy Quest kind of parody: affectionate, loving, but not afraid to poke fun at certain aspects of the classical genre tropes. I’ve read it two or three times now and I love it to bits.
Here’s what I said about it the last time I reviewed it:
I think my favorite Diana Wynne Jones books are when she mixes humor with more serious stuff. The Dark Lord of Derkholm is a great example of that: it’s scary because it dips into the more depressing aspects of humanity, but it’s also really funny because it’s a spoof on swords and sorcery stories.
The world of The Dark Lord of Derkholm is one where an entire planet has been turned into an amusement park for tourists wanting to live the life of what they THINK a (fantasy) adventurer/hero would do. They go on hikes and sleep in taverns, they join in on battles against evil ne’er-do-wells, they follow clues that lead to the one thing that’ll defeat the Big Bad, and then (against all odds!) they DO defeat the Big Bad! I think it’s something like a Ren Faire, only effed up.
Here’s where the horror part comes in: the Dark Lord of Derkholm people don’t LIKE being an amusement park world. Who would? Your town gets taken over and destroyed, your friends and family are killed for a bit of profit, various magical creatures are enslaved or kicked out, huge amounts of criminals are transported in pissed off and weaponized, and you’re not even getting a very big cut of the profits.1 Their society has ground to a halt; they can’t grow anything because it all gets destroyed anyway, their wizards haven’t thought of anything new in four decades, etc. etc. Depressing!
The second Derkholm books is Year of the Griffin, which is also a parody but focused on campus novel/magical school. I’ve only read it once, but I liked it just as much as The Dark Lord of Derkholm and I’d really like to read it again soon, actually.
Here’s what I said about it in my review last year:
I suppose this is the most “Harry Potter”-ish of all Diana’s books. It’s actually set in a wizard school, for example, and there are kids who turn into heroes with the help of both magic and self-reliance and whatnot. But there aren’t any chosen ones, just enthusiastic students who love magic and who want to do nifty things with it. There aren’t really any Voldemorts, either, just stuffy professors whose heads are so far up their rears they aren’t ever getting out again. Also, a bad griffin. Oh, and some assassins and mean parents and other stuff like that. (But no Voldemort.)
If you like griffins, btw, you might like the Griffin Mage trilogy by Rachel Neumeier. It’s not a parody series, and it’s got none of the humor that’re in the Derkholm books, but it’s VERY good and I highly recommend it.