Many thanks for that overview page. I managed to concoct a couple of... statements(?) that sound like they ought to do the trick* based on [url=http://larian.com/forums/ubbthreads.php?ubb=showflat&Number=604088#Post604088]a forum post[/url].

However, in the process of trying to open the "story editor", using the Divinity Engine, and unpacking files, my entire game folder became a fantastic mess. My little addition to the "Start.txt" story file didn't work, either.
I ended up wiping the whole folder, so as to pay more attention to what's going where next time. Is there a guide about which files need to be where, and what the game's directory structure is supposed to look like?



* on CharacterKilledBy, if victim not player-controlled, but attacker (owner) is player-controlled, then InventoryLaunchIterator with a custom event name, handled by a StoryEvent call that takes the item and drops it.