Fable the lost chapters - getting the "infected" trader to barrow fields

Ever wanted to save the trader on the trader escort mission that was bitten by the balverine?

The main thing is that you have to do everything quick.

After you kill the troll in Darkwood Weir, don't wait to get the Xp orbs, just run through the gate to barrow fields

and you should be able to make it before the trader turns into a balverine.