Mariel watched as Dominic Book Hater stepped in front of the fire and cast casually cast aguamenti to extinguish the flames. That looks easy enough, she thought as she shrugged. Wishing to get this part over with and quickly move on to the next part of the lesson, Mariel stepped forward, pointed her wand at the flames, and commanded "Aguamenti." Satisfied with the stream of water emerging from her wand, she stepped aside to allow the next person to take a turn.