They're gone!

Hermione looked over toward the tree, and all three girls were gone. Her eyes widened. "No!", she yelped.

Hermione, faster than she had ever gone, exposing her complete backside to the surface, began to swim as fast as she could back to the tree. She had hoped against hope that the Slytherins would have some mercy, but alas, there was no such luck...

She stood at the tree, soaked, naked, and with all her clothes gone. She didn't even have her shoes left behind!

"Naked..." she thought to herself. "Completely naked and exposed..."

She felt another shudder from her pussy. Had the merman been right? Had she been turned on by all of this?

She looked at the clock. 11:30. She still had 30 minutes left that the Slytherins would think she was still at the lake, but she could still run and get the invisibility cloak and...

"Argh!", she growled. The chill breeze between her thighs kept reminding her of her predicament, keeping her from thinking straight. She leaned back on the tree overlooking the lake.

"Well..." she thought to herself. "I might have time to get take care of that and still make it back in time."

Her right hand drifted down to her groin, and began to play with her clitoris, as her left began to pinch her nipple, making her let out a soft moan.

She didn't want to admit it, but between this and her adventure last night, she was extremely aroused.

As she continued to play with herself, she saw the merman. His arm was moving below the surface in front of him, as if stroking something.

She was embarrassed, but she couldn't help herself. She kept going and going, pinching her clit before moving two of her fingers into her tight pussy.

The merman's movements were getting faster and faster.

After some time, they both climaxed simultaneously, Hermione's juices splattering onto the earth as a fountain of ejaculate briefly spewed forth from the lake.

After she could feel her legs again, she went to the lakeside and quickly washed herself off, the merman smiling and gazing at her below the water.

Hermione looked at the clock tower. 5 minutes until noon. By the time she washed herself off in the waters, the hour was up, and she made her way to the whooping willow to retrieve the invisibility cloak.