"Perhaps we should return to the bookstore to ask."

"Maybe. I don't think we got anything besides plants and required textbooks. Scott, are you okay with heading back?"

He shrugs, and follows the parents. 

Back to Flourish & Botts.

"Have you bought everything, then? Quill and parchment, telescope, ingredients...?"

"Mom, we forgot the telescope!" 

"After the bookstore, and the robes. I'm sure the astronomy supplies are available at night." 

They return to the bookstore. 

There are still many books, and an owner who seems hopeful and then immediately disappointed. 

Do they have anything on law?

There are some books on ancient magical Britain!

The most exciting cases heard by the Wizengamot!

A book about a witch who lived as Muggle for a year!

Not much else.

"Nothing so useful," she sighs.

"This one about the witch might give an idea about the mindset, but not the laws. Probably not worth it. I'll just make a point to ask someone."

"Perhaps our sons should see if they can't find anything related to that in Hogwarts."

"We get a mission? We get a mission!"

He giggles. "We can do that!"

"Alright. Robes, and then Scott and I can double back for the telescope."

And presently: Madam Malkins!

Would they like to experience more Fun With Measurements? 

They'll have to sit through it, at any rate. 

Scott seems vaguely offended by the concept of robes, but doesn't complain.

"You don't like robes?"

"I don't know. I've never worn robes before."

"Neither have I, but they're cool and wizardly!"

"They're all swooshy!"

"Yeah!"

"You can have mine, and I'll wear real clothes."

"Scott, robes are part of the school rules. You don't want to break the rules before you've even been to the castle, do you?"