"I guess this makes sense, in hindsight."
Octavia looked at Rainbow like she'd suddenly sprouted a horn and an extra pair of wings. One might have assumed it was because the pegasus had appeared out of nowhere clad in armour and wielding a sword and floating without really flying, but it was actually because Octavia had heard what she'd said.
And she started to hear a lot of other things, too. Sounds and voices and music, and soon she was walking through town, smiling again, and the world around them looked a lot less grey. She'd already forgotten about Rainbow, and she'd forget about the whole dream when she woke up.
"You figured it out, I see." Luna appeared to Rainbow from nowhere the same way Rainbow had appeared to Octavia. Or probably the same way, Rainbow couldn't actually confirm it exactly. She hoped she'd looked roughly as cool doing it though.
"I didn't think it would leave the sounds on," Rainbow said as the two of them began to walk around the dream, making sure everything was in order. "That's why I didn't figure it out sooner."
"It's easier this way, not so surprisingly if you think about it," Luna explained. "The dream just needs to play out normally and then filter off sounds, instead of rendering the whole thing differently. Makes for better gradual loss and other kinds of simulation."
For a moment Rainbow looked at Luna and not at the dream. "Sometimes you make it sound like dreams exist outside of their dreamers."
"Purely an abstraction." Amused, Luna contemplated a flying turtle pig hybrid. "Everything I usually attribute to the dream is of course executed by a pony's mind. I just find it easier to think of it that way, and in most cases it's the same, it arguably helps in some."