Through Fire And Water is a quest of the Haven playthrough in Might & Magic: Heroes Online.
The hero, per Madog's request, has to go through the cave entrance. There, the hero will face a hellish landscape, as Amber Thorn cathedral has been overrun by demons. The hero has to go to south and help the defenders defeat two lava worms, but also win within seven rounds. With the demons defeated, the hero has to speak to the Amber Thorn lieutenant, who is impressed someone fought their way here.