Since Mia could clearly see where they were headed, she searched for the monster with her magic. It had been drawn to the far edge of the pool when the horses had entered, but now… something was drawing it around. The pull was changing direction, moving around behind them, and quickly.
Ford was struggling, and though she couldn't figure out exactly what was going on as his hand twisted against hers, she figured it must have to do with his horse.
Terrified, she yanked on his arm. They had to move, and now. If the horse was a liability, then they had to do what Grandpa said and release the creature.
At least Harper was behaving!
Ford reacted to her movement by trying to pull away from her, but she gripped his hand all the more tightly. Part of her motivation was fear of trying to make her way across alone, and part of it was terror that he would try and pull something heroic by holding off the monster by himself!