Jan Van Quirm said:
Having mentioned the Dungeon Dimensions, for me this is the last really meaningful time that they feature in a DW book (I don't really count Eric as it's more to do with demonology
), after this Terry's excursions into magical nemesis gets more focussed on Dragons and Elves
et al for a better class of antagonist. Do you think this is because he ran out steam for trans-dimensional monsters in this book?
Both
Guards! Guards! and
Eric came out before MP, so, yes, you're right that the DD make their swan song here, even though he was introducing dragons during this period.
But I don't think Pterry ran out of steam with the DD idea, which was never particularly interesting in itself. I think that after MP he consciously or subconsiously decided to move forward from the "roundworld parody" approach of most of the early books into much deeper and more complex narrative territory. Look at what immediately followed--
Reaper Man,
Witches Abroad, and (the real turning point)
Small Gods, each of which featuring far more interesting ideas. The dogmatic dungeons of Omnia and Alison Weatherwax's mirror universe hold far more compelling terrors...