"That sounds like a step up! I do not want to let this creep out of my sight right at this moment and mirrors or no mirrors the snake is certainly big enough to eat you guys up in one bite so I should be along for better-teacher-fetching too, so I guess he's coming with us. Are memory charms illegal, can he just be turned in or something?"

"I think it's illegal to use on wizards? It's got to be some kind of forbidden to use it on your student. Let's bring him to McGonagall, she'll know for sure."

"All right. Come along, Professor. Lead the way, kids. Ron, I apologize but I do not have a recording of the missing time. It was fairly uneventful though."

"Cam couldn't see Hogwarts because of the anti-muggle spells, so we went looking for a teacher to take them off and ran into Lockhart. Hermione told Lockhart about the basilisk, so he tried to run away and wipe our memories so we wouldn't know he had."

"Alright. Thanks, mate."

Ron and the others set off for, presumably, McGonagall's office.

Wibble. Lockhart follows, clutching his useless icy wand.

"I think maybe you want to put that down because I don't know under what conditions you could cast with it and if it looks like it might be occurring to you to aim it anywhere I'm just gonna wreck it. It's hard to overstate how offensive memory charms are. I will give you a pair of glasses like theirs though." Glasses.

Lockhart maybe did not expect or want glasses spontaneously appearing on his face, but he sure does have them! He jumps. He does also put his wand in his pocket, though.

"Your options are you have that on your person and I'm on a heck of a hair trigger about splintering it into a hundred pieces if you twitch, or I carry it and I am not," Cam tells him. "The glasses are an attempt at an anti-basilisk defense."

He'll hand it over and look extremely annoyed about it.

"Who are you, anyway? I've never heard of you."

"My name is Cam and you wouldn't have. Off we go."

Off they go! More beautiful stone hallways that connect at weird angles, and doors that the kids open by poking them. There are portraits on the walls; some of them wave and one says "Good morning!".

"Good morning," says Cam blandly, and, "are they people?"

"I don't think so? They're more like echoes, or recordings--they don't learn, they can talk about the lives of the people they're based on but not what they did last year, that sort of thing." 

"...okay."

They make one last 270-degree left and Hermione knocks on an elegant wooden door. It's answered by an elderly, stern-faced woman in green robes, who says in a crisp Scottish accent, "Well, this is quite the group. What brings you all here?"

"The monster is a basilisk in the plumbing and also this clown memory-charmed Ron. Hi, I'm Cam."

"A basilisk? Are you certain? How did you come by this information?" She spares Lockhart a "what is wrong with you" glare, but he's clearly not the most pressing concern right now.

"...magic? It's a long story. I can't personally distinguish basilisks from any other sort of inappropriately large snake but it looks like this." He hands her a plastic basilisk. "To scale."

"Wandless conjuration? Without a complete visualization of the object? I find that rather hard to believe." She looks at the kids, then back at Cam. "Can you replicate the third piece of parchment from the top of the central stack on my desk?"

Cam sighs and hands her that too.

It's a subscription renewal form for a transfiguration journal. Her eyes go wide when she takes it. 

"Well. This is unprecedented. I have a lot of questions for you but first I must deal with the danger." Evacuating the school or sending everyone to their common rooms might tip off the Heir, and if they decided to go out in a blaze of glory the consequences could be disastrous, so, "Do you know who is controlling the monster?"

"No, I'm not confident it's a conjurable parameter but if you want a lot of little plastic basilisks we can pan through its history and see if it's been meeting anybody?"

"Unless any of you know where the Chamber of Secrets is, I don't immediately see a better idea. Come into my office." She steps aside to let them into a room balanced on the knife edge between "office of an extremely organized person" and "office of a person with too many jobs".

In they go. "Is he dangerous at all while I have his wand, I'm new to all this wand-related stuff," Cam asks, gesturing at Lockhart. "I can try for the Chamber but the plumbing doesn't obey conventional geometry so I might just wind up with a lot of self-interpolating Chamber parts."