An active, character-driven Hogwarts experience set in the early 2000s. Unique items, plots, and features. Non-canon; this isn't Harry Potter's story, it's ours.
After brewing his Pumpkin juice, Tom's mind was still solidly fixed on potions making. After returning his cauldron to his dorm, he referenced the ingredients he had on hand and a potions book. He noticed a few potions he hoped to make soon that required frogspawn, and so he set off towards the Black Lake to find some, battling the cold from the moment he left the confines of the castle.
As he scoured the Black Lake for the frogspawn, he thought back to that time in 2nd year he and Lindsey had spent an afternoon here after a rainstorm. It made him feel funny inside to consider how quickly time could pass and how things could feel different and the same all at once. He was somehow perceptive enough to realize that this was a problem likely experienced by both Muggle and magical people.
Tom pondered his thoughts as he searched, hoping the cold wouldn't make his search in vain.
Though Tom didn't yet have the skills to gather any tadpoles for use in potions, seeing a lot of them swimming in the cold water by the shore was a promising sign. They kept to some reeds, using it as shelter, and it was where he spotted some empty frogspawn among it.
There was probably some viable ones nearby, though he may have to risk wading a few inches into icy water to further inspect a larger patch of reeds in hope of finding what he sought.
Tom tried not to grow discouraged as he quickly realized he would actually have to venture into the Lake itself to obtain his desired ingredient. After quickly deciding that Madam Pomfrey likely has a cure for hypothermia if it came to it, Tom plopped him down, removed his boots and socks, rolled up his pants, and walked into the water.
It was just as freezing as he’d anticipated- he hoped he could find the frogspawn quickly and be out of the Lake even quicker.
The cold clouded his mind a bit, making it feel as if Tom was in the water much longer than the brief moment it took him to locate some healthy and ready-to-use frogspawn among some of the deeper reeds. He wouldn't have to venture too much further, able to collect two ingredients, but it was just as well.
Seeking a third was possible, but the cold was not kind on him so he'd better make it fast.
Shivering and teeth chattering, Tom wandered only as far into the water as absolutely necessary. The cold felt like it was trying to claw up his body and rip out his heart. He worked as quickly as possible, gathering the two available frogspawn and hightailing it out of the water. He didn’t even stop to consider looking for a third.
As fast as Lightning, he got himself dressed again and rushed to the castle to warm himself by the fire in the Slytherin common room for a moment before beginning his ingredient hunt again.