Sergeant Valiant Charge stood stoically in front of the castle gate, just as he did every other day since his assignment to the front gate detail. It wasn't his dream job, but it beat guarding the latrines or spitpolishing old horseshoes. Keeping a straight face could be difficult, especially with so many ponies seemingly desperate to get a rise out of him, but he was trained by the best. Shining Armor's new training ensured total stoic professionalism, no matter the situation.
 
There was a rumble in his stomach, and the stallion lifted a leg, letting out a quiet fart. If his partner, standing on the opposite side of the gate noticed, he didn't say a thing; As expected for a guard, of course. The rumble grew louder and more insistant, and Valiant Charge let out a longer, somewhat airy fart. There was no smell, but the sound alone attracted the attention of a number of passers-by. The strap over the stallion's stomach began to feel tight, but he knew better than to look down. His eyes remained fixed forward, staring past the assembled tourists into the avenue beyond.
 
“He's blowing up like a balloon!”
 
Valiant didn't need the mare's assessment; He was all too familiar with the bloated feeling in his stomach. It was becoming truly distended now, as if he'd consumed a meal fit for a family, and his strap began to creak. A second later, it burst, and his belly swung free. His eyelid twitched slightly, and he thanked Celestia's teats that the ponies were too busy staring at his growing gut to notice.
 
Gas hissed continually from his rump as it began to round out beneath his armor. This was Shining Armor's failproof training technique; A simple teleportation matrix, one end in an air compressor, the other inside a guard's stomach. It was strange and uncomfortable, but if a guard could keep a straight face while blowing up like a balloon, he could keep a straight face with anything. Shining himself had grown to the size of a hot air balloon before deflating. Valiant wasn't quite as good, but fear of failure had kept his face relatively calm during training. Those who failed were left to deflate on their own, extending their training by weeks as they slowly expelled all the air.
 
Of course, Shining's tests were always relatively controlled, taking place inside the safety of the palace gym. Outside was another, much more dangerous matter; A stallion could float off, or get poked by a bird's beak and... He didn't like to think about it.
 
His belly stretched below his knees, perfectly round and taut, while his legs began to resemble chicken drumsticks. The crowd watched in a mixture of fascination and horror, some plugging their noses despite the scentlessness of his constant expulsion. Always from the basement, never the attic; That was something he'd learned the hard way, watching one of his buddies let out a small belch, and helping squeeze the air from his mountainous gut after.
 
Valiant grunted internally as his belly surged out, his belly button popping out as his hooves lost contact with the ground. A second later, a gust of wind blew through the square, which he doubted was a coincidence, and he blew up with it, soaring over the castle walls. He watched the tourists shrink away, but his face remained solid, as if cast from marble. He was proud of his accomplishment, though he didn't let it show. His body was swiftly losing shape, becoming more and more spherical by the second. His horseshoes became small golden divots in a sea of white flesh, while his cheeks grew to partially obscure his vision. The wind died down, but he continued his way into the blue yonder, propelled by his powerful gas. It wouldn't be long before his commanding officer came to congratulate him for his achievement... Right?
 
Canterlot Castle shrunk away, the pegasi and sky chariots turning into mere dots, before the city and palace itself were nothing more than specks on the horizon. The landscape below him changed from mountains, to forest, to a vast, unbroken grassland. The sun began to set, and yet the stallion continued, propelled by his ass and the occasional gust of wind. In the distance, he saw the coastline, with breakers crashing upon the jagged rocks.
 
For a second, the stallion's expression turned from stoicism to fear as he imagined being lost, floating away across the sea to the unknown lands beyond, or floating into the upper atmosphere and suffocating as the air became too thin... And then, he felt a twinge of pain in his stomach, and realized his mistake.
 
Sergeant Valiant Charge exploded with a meaty slap, shreds of fur and twisted armor raining upon the scenic meadow below. Back in Canterlot, Celestia sighed, turning from her scrying orb and switching off the air compressor.
 
“I just don't get it,” She muttered to herself, “This is the fourth one today! Maybe I should ask Shining how he did it.”
 
After a moment, she shook her head and laughed, “Nah, I'll just keep trying! Somepony's bound to pass eventually!”
 
Her horn ignited, the compressor began to hum, and outside the statue garden, a guard let out a deep, rumbling belch.