Believe it or not, I’ve seen worse.
Luz officially passes the “entrance exam” (by which we mean showing Principal Bump that she knows two spells and is eager to learn more, despite her lacking showmanship). So she’s off to magic school!
Eda: What are you nervous about? You’ve been to school before.
Luz: That’s why I’m nervous! At my human school, I didn’t make a good first impression. This is a chance to be seen as something other than a screw-up.
Eh, popularity is overrated. Besides, as long as she doesn’t get on Amity’s bad side again, she’ll probably be fine.
First, she has to decide her future. No pressure at all!
Principal Bump: Now, today we’ll be visited by the Emperor’s Coven for a routine inspection. If we want to impress them, you’ll need to join a coven track before they arrive.
Luz: Actually, Principal Bump, I’ve made my own schedule. […]
Bump: Studying multiple tracks at once? No one does that.
Luz: Then I’ll be the first!
Bump: No, you won’t. According to the rules, a good witch needs to hocus focus! You can only pick one of the nine tracks. And you do not want to embarrass me in front of the inspector.
Luz: But all the tracks are so cool! Is there some sort of enchanted article of clothing that could sort this out for me?
Bump: Well, there used to be, but…
In lieu of feeding Luz to the Choosy Hat, Bump somewhat arbitrarily chooses Potions for her.
Unsurprisingly, she quickly loses interest in light of the many other magical things at magic school. And is promptly condemned to the Detention Track for “mixing magic” (aka picking up a crystal ball).
She does make a good impression on the fellow detentioners, but as they teach absolutely nothing in the Detention Track, she’s keen enlist the help of Gus and Willow to help her get out, even if it does mean potions ’till you die.
Viney: You’re one of us troublemakers now, so you get special access to the secret room of shortcuts!
But it turns out that they’ve discovered a way to get around the lack of access to the school.
Amity: So you two go to the same school now! That doesn’t change anything…
Nothing to see here!
Luz: This place is amazing! I bet you guys can get into so much trouble in here.
Viney: Sure we can! But we can also do so much more.
Viney: We’re not allowed to study any kind of magic. So we study every kind of magic! In secret.
Luz: You actually like school?
Viney: Yeah, we might’ve liked it too much…
They all got sent there for “mixing magic”, too, but in more intentional ways than Luz (Bump was presumably extra strict today because of the inspector).
Viney: We all want to be in more than one coven track, but Bump just says we need to “focus”.
Luz: Sounds like Bump’s priorities are out of whack.
But just then Gus and Willow show up to rescue her from detention, because Luz was very understandably upset about her situation before they invited her into the secret hideout, and this fuels a contrived misunderstanding that should have been resolved in a minute. But thankfully it doesn’t last too long, as an actual threat turns up.
That inspector turned out to be a basilisk in disguise.
Principal Bump does step in to try and protect his students as soon as he realizes what’s going on, but it overpowers even the teachers.
This is an interesting representation of a basilisk, as it’s essentially a magical vampire (with shapeshifting abilities, too), consuming the magic of its victims and rendering them powerless. Incidentally, the basilisk in Harry Potter also had some unique powers, as in Greco-Roman folklore, the basilisk only killed those who looked in its eyes; the petrification thing was borrowed from the Gorgon.

Luz: It must have attacked the other schools, and now it’s come for us. We have to do something!
Jerbo: But if Bump catches us mixing magic again…
Viney: He’d kick us out of school.
Luz: Hexolios are out there getting hurt, and we’re the only ones who can save them! We’re troublemakers, right? So let’s get out there and make some trouble!
And so they defeat the basilisk by mixing magic! And a little bit of Luz’s paper spells.
Luz: You did it! You were amazing! You guys-
Bump: Are in so much trouble! Leaving your homeroom, mixing magic, and is that a secret hideout?
Luz: Yeah, it is. But let’s think about this, Principal Bump. Why would kids in the detention track need a secret hideout?
Bump: I don’t care to know the ins and outs of rascality. But if the Emperor’s Coven can send an actual inspector this time…
Luz: Okay, you need coven money. But if you have to hurt your students to get it, what’s the point? They saved Hexside, they should be able to study what they wish!
Bump’s at least humble enough to admit when he’s wrong, so all of the detention students get to study in dual tracks.
Luz: Maybe it’s crazy, but I wish I could study a little bit of everything.
Evidently a little bit of everything EXCEPT potions (which is yellow). Not that I blame her – if it’s anything like chemistry, I totally understand. You either love it or you hate it, and while the potions teacher here is nothing like Snape, she certainly didn’t make the subject seem exciting.
Until next time…