Read the following excerpt from a story and answer the questions that follow.
"The wind howled through the trees, and the leaves rustled restlessly on the ground. Mara wrapped her scarf tighter around her neck, but it did little to shield her from the biting cold. She glanced up at the mountain path ahead. The trail seemed endless, yet she knew she couldn't stop now. 'Just a little farther,' she whispered to herself, forcing her legs to keep moving."
What is the tone of the passage?