Twilight, Light, and Double appeared on the streets of Ponyville just in time to see Twilight’s library explode. Fire shot out of every one of the castle’s first floor windows, and sheets of flame licked up towards the second floor.
Behind them, Ponyville’s clocktower exploded. A bomb made of steel and TNT fell through the roof of a house made of wood and thatch. The house vanished into nothing.
“The caves under the town!” Twilight shouted. A beam from her horn projected a massive purple forcefield over half the town. No sooner was it established than four bombs struck it, blossoming into flame above the terrified ponies she’d saved. “Maud’s house. It’s our only hope. They’re a bomb shelter that can hold everypony. I’ll take care of Light you herd everypony down there.”
“Right.” Double stole one last look at Light Step, and then in a flash of green, transformed into Twilight. In a superb impression of the Royal Canterlot Voice she boomed, “Everypony run to the caves! Run to the caves under the town!”
She galloped into Ponyville, shouting her message as she went. The real Twilight focused on her shield spells, trying to toss up as many force fields as she could.
Light Step stared at the castle, eyes wide in shock. The first floor was obviously gone, but the higher floors were still intact. They could be saved, if the flames could be prevented from spreading. She watched as the flames licked their way up from the first to the second floor.
“We can still get it before it’s all gone,” Light said, taking a half-step towards the castle. Her tone was distant.
“Sorry, Light,” Twilight said. “You’re a non-combatant. The best way for you to help is to get to safety so I don’t have to worry about you. Get ready to teleport.”
Before Light could object, she vanished with a pop.
She appeared over Maud’s bed, landing directly on top of her and Mudbriar.