Why can't we do this? You can destroy the Dark Brotherhood as an option, why not be able to destroy the Thieve's Guild? I think it should be an option when you listen to Brynjolf's scheme (Plant Madesai's ring on Brand-Shei OR [insert objective to destroy thieves guild]). The only problem that could occur is if you are in the DB and you accept amaund motierre's contract (I won't say too much for spoiler's sake). Not to mention the 'Unusual Gem' would be obselete ... But there could be work arounds, right? What do you think?