McDougal and Edward [calmly] in “Unfinished Business”

[looking at Alphonse's armor] There's no one in there. It's empty...! But that... that could only be true if his soul was bonded to the armor... So you lost your arm...and your brother... he lost his entire body... Heh! I see... it all makes sense... You fools committed the ultimate taboo! You attempted human transmutation, didn't you?! Alchemy's one and only unforgivable sin!

You know... There are some lines you really shouldn't cross. [punches mcdougal in the gut]