In some times and places and worlds, Merrill would have run out of spells by now and had to fall back out of the line of fire while her blade-bearing friends sliced the dragon to ribbons. Fortunately, this is not one of those worlds; she does have to pause long enough to swallow a lyrium potion at one point, but then it's right back to freezing as much of the dragon and its environs as she can manage. Which comes in awfully handy for Isabela and Hawke, since it means the dragon's spending more time screaming in pain than breathing fire.

The thing's not going to last much longer at this rate, even if it does manage to get off the ground again.