I just started playing this game after taking advantage of the GOG discounted offer.

I know that Dark Eye has a history of other games, but I feel like I've been dumped in the middle of a story... Is there another game or novel that explains Geron's back story or am I missing something?

Take the academy of magic... Geron says something like "I'm not going to try sneaking back in there again."

Anyway just thought I'd ask... Just a horrible feeling I get like I'm missing half the story, like sitting down to watch a movie after it's already been on for 30 minutes.

Geron occasionally makes references to his past life, but there isn't a prequel to the game and Chains of Satinav is the first game of it's series. It has later sequel called Memoria, which will continue Geron's story.

There is a section in the manual, "The Story So Far", that explains anything that should be known to understand the story (and even then, most if not all that information is revealed at some point or another during gameplay).

The rest, like Geron sneaking into the Academy, makes sense considering his personality and background, but is not relevant to the plot of this game. It does add flavour; Geron has lived all his life in Andergast so it's understandable that he has a history with the inhabitants of the city.