During the Summer Festival in Canterlot, a construct of rock and crystal emerges from the mines under the city, and attacks anypony who is using magic.
Moonshine sees it emerge from the lake and trails it to the Festival plaza, where it is engaged by Tempest and Blue Venture. Tempest attempts to push it back with a Rainboom, but only damages it. Bee drops an object on it and discovers that the crystals growing from its back are vulnerable to attack.
Steel Striker arrives and engages the monster, pulling its attention away from the guards it was pummeling. Striker endures three direct attacks by the creature because she is a badass. Tempest yells at Striker that she is a badass.
Moonshine attempts to damage the monster with thrown potions, but they are not accurate enough to hit its weak points. Shadowblossom arrives and creeps up on the creature, waiting for an opportunity.
Curtain Call helps to clear the crowd out of the plaza.
Tempest tries to drop an object on the monster, but she is not strong and her improvised attack fails. Shadowblossom scores a substantial hit on the monster’s knee joint. Tempest and Bee move to help the pegasi guards that have been downed. Tempest says some inspirational words to Striker, after the latter is wounded by the monster’s shrapnel attack. Moonshine moves forward to help Striker with a healing potion.
Curt sees that everyone is on the ground in striking distance of the monster, and casts mage armor on himself to attract its attention. This strategy is wildly successful. He dramatically dodges two of the creature’s attacks in the center of the plaza, before Tempest destroys the monster with a rainboom attack.
Curt then faints.
A surge of electrical magic leaves the monster as it crumbles, and is seen to infuse each of the six ponies. The onlooking crowd at the edge of the plaza loses their shit.
As everyone gathers around Curtain Call, Hard Point, the Captain of the Royal Guard, arrives and asks that the group wait to speak with someone in high authority. Curtain is nervous and attempts to charm the captain, and is held by the guards. Moonshine protests that she didn’t really do anything.
A crystal earth pony arrives, identifying himself as Mister Clear. He requests that he be allowed to teleport the group somewhere away from prying eyes and ears. They arrive in a dark, musty hallway, and Crystal Clear leads them to a gloomy room with six throne-like chairs surrounding a large round table. The cutie marks on each chair are legendary.
Clear explains that the last time something like this happened, 25 years ago, it was the precursor to tumultuous times. He was part of a group of friends that stepped up to fight the chaos and to be an inspiration to ponies everywhere. He suggests that it may be the time for another such group, and this one just made an incredible impression on the citizens of Canterlot.
They are interrupted by the appearance of a golden light at the head of the room. Princess Celestia stands in the doorway.