Twilight's Growth Sneeze

It was a wonderful day in Ponyville. Twilight was at her house, doing some experiments. "Spike!!" shouted Twilight. Spike ran down the stairs to the basement. He can see Twilight was working on a new potion to turn a solid into gas. "What is it, Twilight?" Twilight turn to Spike and said to him, "Can you get my book for Gas formations, please?"
"Sure. I'll go get it," replied Spike as he ran up the stairs.
Two minutes later, Spike returns with the book. "I got the book, Twilight." Twilight use her magic to grab the book and puts it on the table. Twilight turns to the page that says "Solid to Gas in a Quick Sweep." She used her magic and put a orange liquid in the beaker and puts the beaker on the heater till the liquid was bubbling. She waited for several minutes till finally the liquid bubbled quickly and was time to put the next item in.

She uses her magic to grab a test tube this time with purple liquid inside. "Easy. Easy," she said as she tipped the tube over, then a drop of the purple went into the beaker and causes the liquid to bubble rapidly, then it went puff. "Now its time for the test." Twilight's magic use a gem she bought from Rarity and drops it into the beaker. The beaker shakes wildly and pops out a red gas. "Too toxic. Getting dizzy." Twilight coughs, then passes out as the whole room is engulfed in red smoke. She uses her magic to make a fan and the fan blows the red smoke away.

"Twilight! Twilight!" Spike shouted as he ran downstairs and sees Twilight laying on the ground. "Uh oh." Spike uses an empty beaker and fills it with water. He runs over to Twilight and splashes her with water. "Huh, what happened?" asked Twilight.
"You did the experiment, but passed out," Spike explained.
"Well, thanks for waking me up from the gas, Spike," replied Twilight.
"No problem. What are friends for?" Spike and Twilight clean up the exposed gas in the room. Twilight sneezes but Spike didn't noticed that Twilight was a foot taller. When they were done, they walked upstairs to the library. "Twilight, have you noticed anything different about you?" Spike asked, curiously.
"Nope," replied Twilight.

"You're a foot taller than your normal size." Twilight was shocked about what Spike said and ran and saw in the mirror that the tip of her horn was on the top of the mirror.
"You're right, Spike," said Twilight.
"Does it have to do with the gas?" asked Spike. Twilight wasn't sure but she only know that a foot isn't that bad. But what she doesn't know is that she and all of her friends are heading for really, REALLY, REALLY big trouble.