I beat the game years ago so I don't remember the details, but there are many great walkthroughs for the game
here. One thing I do remember, though (spoiler): The boss you get at the end of this level is the only real difference you'll notice if you play the game multiple times, choosing different paths for Augustus. All three of the bosses are beaten in essentially the same way (though you have to use different elements in your spells). That's another thing I disliked about the game: I played it three times to get the alleged "uber ending" (which sucked, by the way) and all three times it was
exactly the same. It was boring the
first time, so it was a chore to play it two more times.