Deep in the Shang Tu Royal Laboratories, a father‑and‑daughter team are in the middle of an experiment involving an energy crystal. The father, a hedgehog with vanilla fur and purple spines wearing navy blue trousers and a grey polo shirt, monitors a series of readouts while his daughter, a hedgehog with peach fur, pink‑tipped purple spines, and a black tank top paired with royal blue capris, carefully manipulates a series of probes arranged around the crystal.

"Careful," the elder hedgehog advises. "Reading an unusual spike on probe gamma."

"On it," the younger hedgehog acknowledges, fine‑tuning the position of the probe.

"OK, that's good," the father confirms. "Safety glasses on."

The daughter nods her head, causing her safety glasses to fall into position. "Good to go," she confirms, pushing the glasses up her nose a little.

"On my mark: three… two… one… go!"

The daughter flicks a switch to begin the experiment. For the first few seconds, everything proceeds as planned‑

The crystal suddenly explodes. Surprised, the daughter yelps and pushes backwards, falling off her stool and landing hard on the floor.

"By the Ancients, are you OK?" the father asks, clearly worried.

The daughter sits up, shakes her head, blinks furiously for a few moments, then answers. "I'm fine. Just a little shaken, s'all."

The father helps his daughter to his feet. "And this, Sally, is why I keep suggesting you let me do the dangerous part," he reminds.

"You don't have to worry about me, dad," Sally assures. "Besides, being younger, I'll recover quicker if I do get hurt."

The father smiles warmly before turning to the experimental set‑up. "I'm starting to think we may never find a way to supercharge these crystals."

"We will," Sally assures. "We've got closer than anyone has ever got before, and I genuinely think we're only one or two tweaks away."

"And that's why I'm glad you're working with‑"

An urgent knock at the door interrupts them. Curious, the father answers the door.

"Matthias, Sally, the Magister wishes to speak with you urgently," General Gong informs.

Matthias and Sally exchange curious looks. "We're not in trouble, are we?" Matthias asks semi‑seriously.

"On the contrary," Gong assures. "You're about to receive your greatest assignment yet."

The general steps to one side to allow the Magister to enter the lab. Surprised, it takes a moment for Matthias and Sally to react and bow respectfully.

"This is indeed a humble honour, Your Excellency," Matthias greets.

"At ease, Matthias," the Magister instructs.

"Thank you, Your Excellency," Matthias replies, relaxing as instructed. "May I ask why this surprise visit?"

"You may," the Magister assures. "Earlier, a curious event occurred: an active member of the Red Scarves sought and received audience with me to request we store and protect a collection of five gemstones with extraordinary abilities. She was even kind enough to perform a small demonstration, in which she conjured fire from thin air using nothing more than the ruby held within this box."

"Forgive me Your Excellency, but that sounds highly unbelievable," Matthias replies.

"I thought so too, until I saw her demonstration," the Magister admits. "And while I am no expert, I have taken a closer look at these Elemental Crystals, and there is clearly something about them that marks them as very different to anything we've seen before."

"May I look at them, sir?" Sally asks.

"Of course," the Magister agrees, opening the box.

Cautiously, Sally approaches the Magister and the box, and takes each Crystal in turn, looking at it very closely. "There's definitely something unusual about these," she concludes. "This ruby looks like it has flames writhing inside… the sapphire has something resembling crashing waves… the emerald appears to have a tree swaying in the breeze… the citrine has an eternal landslide… and the diamond has… something, can't tell what it's meant to be. Clearly, each one matches to one of the five elements of the wǔ zhǒng liúxíng zhī qì. Though the Wood Crystal should be sapphire, and the Water Crystal should be onyx, if they were to be completely accurate."

"Young minds move quickly," the Magister compliments, causing Sally to blush. "I trust you will both apply yourselves to this research in the manner that has bought you your reputation as among the very best."

"Absolutely, Your Excellency," Matthias assures.

"You can count on us!" Sally chirps. "Your Excellency," she adds almost as an afterthought.

"Excellent," the Magister acknowledges, closing the box. "You'll begin tomorrow. Until then, the Crystals will be secured in the laboratory you will be using from now on. Your access will be granted before tomorrow morning, and aside from myself and General Gong, you will be the only people with access. Please do not allow others access to them. Failure to comply will be met with the strictest possible punishment."

"Of course, Your Excellency," Matthias and Sally agree in unison.