Piper was worried that none of Isabella's magic was going to work, and was preparing for the worst when she cast the spell. Fortunately, it worked, and Isabella was saved from that demon. However, Piper began freaking out when she saw the one last fireball heading towards her. She knew that she couldn't stop it as she was protecting herself.
Piper herself froze when she saw what happened. The blue shield protecting Isabella looked awfully familiar, and it did the exact same thing that hers had done. She finished freezing and blowing up th remaining demons, then stared at Isabella in shock. "What was that? DId Wyatt cast a spell on you?"