Lena loved exploring the forest near her house, always searching for new adventures. One afternoon, she discovered a hidden path covered in bright yellow leaves and decided to follow it. As she walked, she heard a faint meowing and found a tiny, shivering kitten stuck under a fallen branch. Just as she lifted the branch, a grumpy old man named Mr. Grayson appeared and scowled at her. “That kitten is a nuisance,” he growled. “Leave it be!” But Lena refused to abandon the helpless kitten, determined to take care of it and find its owner.
Who is the antagonist in this story?