Beatrice was at the lake because of her nightmares. She claimed to see a large tentacle coming out of the water, so she jumped in to try and do something to help the Circle of Khanna, but she ultimately wasn't a strong swimmer.
Snape concluded that Bea's nightmares were a result of her repressing her trauma. He used Legilimency on the girl to get to the root of the problem. After spending some time with Beatrice, Lana felt that the girl was finally starting to move on from her past, and that she was acting like her old self again.
Beatrice also told Lana that she dreamt about a giant squid beneath the black lake, and Lana decided to call together the Circle of Khanna to discuss what may lie beneath the lake if the final vault was indeed in the actual water. They were currently all in the DADA classroom.
"Everyone, listen up." Lana called, gaining everyone's attention, "It's time we moved forward with finding the last vault. It seems very likely that it's located in the black lake. So we'll need to be prepared for whatever the lake throws at us. What sort of dangers could we expect to encounter?" she explained, as Merula and Ben stood by her side.
"Tentacles, grindylows, merpeople...it sounds like we still don't know enough about the lake." Lana listed after their discussion.
"We know the grindylows are dangerous, but we can't say for sure whether the giant squid poses a threat." Charlie told her, "Let alone the merpeople."
"And we still don't know how best to combat the grindylows, if the need arises." Diego added.
"I hope it doesn't." Liz worried.
"In other words, we're still in the dark. What we need right now is an expert opinion." Lana said, "Lets go have a word with Kettleburn. A discreet word, if possible."
Lana, Barnaby, Charlie, and Liz all headed down to the creature pen, where they found the old professor tending to an abraxan.
"Hello there, my young creature experts! If you're here to play with the bowtruckles, I'm afraid you're too late. Your classmate Alanza came by earlier, and they all ran off after her! She truly has a way with the wee beasties." he chuckled.
"Actually, we wanted to ask you about the creatures in the lake, professor." Lana told him.
"The black lake, specifically." Barnaby added.
"I appreciate the clear communication, Mr Lee." Kettleburn laughed, "So what would you like to know about our lake-dwelling friends?"
"Which of the lake creatures is the most interesting?"
"For my galleons, the giant squid is in a class all its own. I'd love to devote a summer or two to studying it. Although, the grindylows are arguably more interesting lately..."
"What's been going on with the grindylows?" Lana asked.
Before the man could answer, Alanza walked in with a cluster of bowtruckles surrounding her, followed by Hagrid.
"Ah! If it isn't the bowtruckle charmer herself." Kettleburn cheered.
"It wasn't on purpose! The little fellows can't seem to get enough of me." Alanza said as some of the bowtruckles hopped on a nearby rock, Barnaby immediately going over to see them.
"Yeh might've stepped in some dragon dung. If there's one thing bowtruckles like, it's fertiliser." Hagrid added.
"Are you saying I smell like dragon dung?!"
"Looks like you've stepped in something yourself, Hagrid." Lana laughed.
"Ah, I didn' mean it like tha', Alanza! I'm sorry." Hagrid apologised.

YOU ARE READING
Barnaby Lee x Reader - Year 6
Fiksi Penggemarhi! this is book three in my Barnaby x reader series :) again, I suggest you read the others if you haven't, just for context yk anyhoo, please enjoy! <3 Highest Rankings: No.1 in #barnaby (wtf XD) No.1 in#barnabylee (😳)