The story is going very nicely. There are some issues with your writing style itself, but they will clean up over time.

Things like swapping between US and UK style punctuation, there was one paragraph where you had Raarg and Rarity both talk (generally you keep character speech to their own paragraphs). Also, don't be afraid to mash paragraphs together if one character continues talking, I noticed that a lot in the first chapter.

Good luck, and please, keep writing!

7437786 Thanks, I'm finding I'm improving and changing as I go. The paragraph mash is because I write the story on a separate word document then copy/paste it onto the site. With Chapter 1 it worked fine. But with this Chapter it mashed all the paragraphs together and I had to manually separate them.

I will try to watch the punctuation. So far, getting it right has been my biggest technical headache.

7437808 I get the same problem, it occurs when the word processor's settings are for 'auto paragraphing' or such. But yeah, getting better with each chapter is good!

Raarg and his cohorts aren't terribly wise, I must say. They're literally courting annihilation. Sure, they have a treaty, but they've also made off with one of Equestria's most important national security assets. All bets would be off once the Diarchs find out.

Poor enslaved Rarity, perhaps to become a sex slave of the Diamond Dogs.

the genteel, polite and docile pony in his arms

*gentle

7598817 Nope, I did indeed mean 'genteel'

The two dogs stood there, dumbfounded, trying to mentally catch up, as Rarity effortlessly shifted their paradigm on captives without a clutch.

oh, that made me think of this old cartoon:
http://dilbert.com/strip/1995-08-25

8076010 Curses...you've found my secret lair of references!

I mean, I get that there's a treaty and all, but they still captured one of the six most important mares in Equestria.

Ooooh, when Twilight hears about this...

8239974
Twilight gets involved, significantly