James addressed the Marauders, Gwen, Snape, and Regulus in a serious voice. "The Sunken Vault is hidden in the depths of the Great Lake," he explained, as he unfolded a detailed map of the lake in front of them.
"To get there, we'll have to borrow Hagrid's boats and sail to this specific spot," he continued, pointing his finger at a location on the map. "Once on the surface, we'll dive using gillyweed. We should find a hidden mechanism, perhaps a button or lever. That will trigger the entrance opening. Questions?"
This is the last meeting before their last adventure. They had to get everything straightened out so that nothing goes wrong tomorrow.
"Shall we do it in the evening?" asked Peter, and James nodded. They were not to be seen for obvious reasons.
"B-but it's winter... It'll be very cold and colder at night," said Peter, swallowing his breath. The last thing he wanted was to plunge into the great lake at night.
"Don't be a coward, Peter. It'll just be a dip," Sirius said.
"The gillyweed helps you to adapt to the cold water temperatures. You won't freeze if you take that first and then dive," James explained, soothing Peter's worried expression.
"We may encounter hostile sea creatures as we descend, so let's go back over the information on those creatures," Lupin said, unrolling a scroll.
On their dive tomorrow, they might encounter:
Grindylows: They are aquatic demons with a height of 4 feet, horned, and pale green skin. They are considered dark creatures as they are hostile and their diet includes humans. Classified as XX.
Selkies: Scottish mermaids, which are not at all beautiful like their warmer water counterparts. From the information they obtained, there is a colony of selkies in the Great Lake, and they are not at all friendly, so they must be careful. Classified as XXXX beasts.
Kelpies: Aquatic demons capable of shapeshifting. They usually take the form of a horse, and humans also enter their diet. Classified as XXXX beasts.
"Those are the most dangerous beasts we may encounter on our way. I am more concerned about the Selkies. They have a colony, so they must be very numerous. We don't know where exactly the colony is in the lake. We would be very unlucky if it is near the entrance to the vault," Lupin finished his report.
As expected, Peter had a pale expression, and his fears were once again present.
"Stop being such a coward. I'll protect you," Sirius said, annoyed at Peter's exaggerated expression. Even Toby had become much braver after experiencing all of James' adventures and training.
"For the Grindylows we will use the repulsion spell. If used on water its effect changes and causes a jet of boiling water to shoot out. This will drive these little devils away. For the Kelpie, we will use the charm of placement. That way they will become docile and harmless..." explained James giving a demonstration of both spells. Pronunciation and wand movement. Mostly, for Peter. He didn't want him to get hurt like last time.
The others were geniuses like him who mastered these spells easily. Toby with hard work, training, and experience from recent battles had become very capable. He was no longer the shy and nervous first-year boy.
"What about the Selkies?" asked Regulus with a raised eyebrow. It was no joke facing dozens of XXXX-rated beasts.
"There's a village under the great lake. Dumbledore and the school staff must be aware of the existence. They must have some sort of agreement that they will not harm the students, or they could bring about their extinction. They are more intelligent beings with a civilization unlike the other two. I don't think we are in any danger, and they are probably just watching us, but if there are any attackers we will use Diffindo spells. Because of the water pressure it is the only spell that can be effective," James explained, and everyone nodded.
Spells such as Petrificus Totalus, Immobulus, etc. Would not reach long distances because of the water pressure, unlike the Diffindo which is cut with power that can make its way.
As for the giant squid that lived in the lake they knew that it was semi-domesticated, even allowing the students to tickle its tentacles on sunny days when it rested in the shallow water. So they did not fear for this creature.
"What about the spy rats?" asked Sirius with a slight frown. By spy rats, he meant Lucius, Rabastan, Anastasia, Mark, etc.
"They never tire of watching our every step," Snape commented with a grimace. If he wanted to leave his common room at night to head here or to the Room of Requirement he always had to sneak out so he wouldn't be caught by them.
"We will defeat them before we leave the castle and head for the lake. At midnight you guys must leave your common room," James said, looking at Gwen, Snape, and Regulus.
"Come out no matter what. We'll already be waiting for you," he added, and the three Slytherin students nodded.
With a few more arrangements the meeting ended, and they returned to the castle cautiously. The spy rats were not after them tonight, so they were able to get to their common rooms without much trouble.
The next night the time came. Fifteen minutes before noon the marauders emerged from the Gryffindor common room. To everyone's surprise, no one was spying on them.
James cast the charm Homenum Revelio several times, but no one was hiding to spy on them. Their journey to the dungeons was without difficulty.
They had to wait a few minutes, as they did not expect to have such a clear path. At noon that night, the Slytherin door opened, and out came Gwen and Snape. Behind them, under the invisibility cloak, followed Regulus.
They did not head straight for the outskirts of the castle. They circled to make sure no one was following them. They passed Filch and his cat a couple of times, but thanks to the cloaks and the charm of Silencio Barriera they were not spotted.
After making sure there were no rat spies following them, they left the castle quietly, moving quickly and cautiously. They knew exactly where Hagrid kept the small boats that were used to transport the first-year students from Hogsmeade station to the castle. There were a dozen boats on the dock, tied together with thick ropes that held the small craft in place.
The night was cold and dark, with a sky overcast with thick clouds that threatened snow. The icy wind blew across the lake, causing the cloaks and scarves of James and the others to swirl around them. The Great Lake stretched out before them, its surface seeming as black as the abyss, barely reflecting the lights of the castle in the distance.
James' eyes roamed the row of boats until he selected two. With a Difffindo of his wand, he cut the ropes that held them together. The sound of water splashing against wood echoed in the cold air.
James, Gwen, Sirius, and Peter climbed into one of the boats, while Snape, Regulus, Remus, and Toby settled into the other.
The lake water was eerily still, and they could barely see more than a few feet in front of them. They activated the Lumos charm, and the soft, bluish light from their wands dimly illuminated the path through the darkness.
"Take it easy, Peter. No ghost will come out of the water to eat you," Sirius said with a chuckle. He loved adventures of this caliber, unlike his cowardly friend.
Peter's face paled at the mention of a ghost that might come out of the cold waters of the lake.
"Stop bothering him," Gwen said, looking at Peter's pale face. She didn't want Peter's fault for canceling the expedition.
James and Lupin looked at each other and nodded. Then, they activated the boats easily. The boats didn't need oars; they moved on their own. They began to glide smoothly across the surface of the lake. They knew how to control them thanks to Hagrid. Always they visited his hut to keep him company and to have him tell them stories, and in the process, they got useful information.
Guided by the faint light of their wands, the boats began to move forward, breaking the silence of the night with the faint sound of the water parting under their hulls. They were getting closer, and closer to the center of the lake, where the water was deeper and darker.