"I was able to modify the rebreathers used by my scouts to be lighter and less cumbersome." said Twilight, gesturing to the clear masks and opaque oxygen tanks on the table between her and the pegasi.

"The tanks don't hold as much O2 as the normal ones, but they shouldn't hinder your escape either. Just to be sure though, I’d discard them once you’ve risen above the clouds, since by then you won't still need them anyway. If all goes according to my projections, there shouldn’t be enough fuel in the valley to sustain the blaze after the gas is gone so you should be clear to return to the bunker sooner rather than later.”

She stepped aside and gestured toward the heavy, suitcase-like device on the floor next to the table. "This will be impossible to fly with, which is why you will have to hoof it to the breach." she said. “I realize it’s inconvenient, especially considering the smaller oxygen tanks, which is why I’ve attached a couple of spare ones to the device. Just remember to hold your breath when switching tanks. Even a single lungful of the toxic vapor can make you sick.”

The pegasi were paying close attention, neither of them feeling particularly confident about the task ahead. They wanted to make sure they were as prepared as possible. As they seemed to have no questions, Twilight decided to continue.

"You can take turns carrying the device individually, or you can share the load." said Twilight, directing their attention to the handles on the top and sides.

"Now this is of particular importance.” she prefaced. “Once you have reached your destination you will need to arm the device by entering a code into the keypad on the front." She knelt down beside the device and placed her hand underneath the keypad, effectively underlining it. Then she lowered her hand to reveal something else.

"The code is written on a sticker below the keypad, in case you forget. This isn't a lockbox, after all, and I'm not worried about any-pony trying to steal the device or otherwise interfere with the mission. The device won’t work as an explosive outside of the fog anyway.” she said, then stood up again. She had been fighting the urge to yawn, but when she tried to stretch her lower back one escaped anyway. Dash and Ditzy were too on edge to yawn in return, which was probably good in a way. It wouldn’t do for them to get drowsy while out in the fog with severely limited oxygen.

"Once it's armed, you will have about a minute before it releases the compound. Toss it in as quickly as possible, then fly straight up. Don’t wait for confirmation, just get out of there fast.”

Twilight looked each of them in the eyes in turn, her expression serious. "Do not waste any time. I mean it. If you aren't out of the clouds by the time the compound is released and mixes with them..."

She didn't have to finish. Every-pony understood the risk. They also knew what was a stake, even if it seemed somewhat far off. If there was a chance this stuff could spread to their homes back East, then they were not going to roll the dice.

"We won't let you down, Twilight." said Dash, raising her hand and clenching it into a fist, as though seizing the very air. Her cocksure grin belied the nervousness she felt, but fear was no excuse to act afraid. She had no intention of being vaporized, and she hoped that her display would ease the worry of her friends, if only a little.

Twilight smiled a little, then pulled a chair from one of the desks and slumped into it, exhaling wearily. “I’m sorry to put so much pressure on you two. I didn’t expect to come across something like this. I should have known there would be peril, but the kinds of things I’ve seen since the princesses ordered these expeditions have been both wonderful and horrifying.”

Ditzy stepped up to Twilight and out her hand in her shoulder. She looked down at her with her uncovered eye and smiled. “Don’t worry Twilight. We’re good at this sort of thing. You’ve done your part, now let us do ours.”

Dash and Twilight were surprised by Ditzy. She had been silent up until that point, yet the confidence and sincerity of her words rallied their spirits.

“Thank you, Ditzy.” said Twilight.

With oxygen tanks lashed to their hips, hoses trailing from the masks hung around their necks, Ditzy and Dash stood before the airlock with the heavy device on the floor between them.

“Ready?” Dash asked of Ditzy.

“I guess so.” Ditzy replied, not sounding as confident as she did earlier.

Dash put her arm around Ditzy’s shoulder and drew her close.

“Hey, we survived that drake, didn’t we? We’ll be alright. You’ll see.” said Dash.

Ditzy smiled. Dash was right about the drake, and they had over come other obstacles before that.. Maybe things really wouldn’t turn out to be a disaster after all.

The two bent their knees in unison to grab the handles of the device and lifted it up. From behind the glass view-port Twilight gave them the go-ahead to step forward, removing the first magic barrier and replacing it behind them as they did. Once the two of them were inside the airlock they raised their masks over their muzzles and gave Twilight a thumbs-up, letting her know they were ready for her to remove the external barrier.

The gas flooded in quickly and was surprisingly cool, like morning mist. They shook off the chill and stepped forward, matching their stride and carrying on out of the cave into the valley proper. Behind them, Twilight ushered forward the rear magical barrier in order to force out the vapor and effectively flush out the airlock, restoring it to the way it was.

They were on their own, now.

Author's Note

Took me awhile to figure out how I wanted to do this, end ended up breaking what I wrote into parts again.