"Sister?"
"Mmph..."
"Sister, wake up."
"Nnh... Luna? What time is it?"
"Just after midnight."
"...Are you serious?"
"I know you had a long day, but something's come up and I must speak to you."
"Well then, speak, by all means. Wait – let me put a light on... There. Now what's going on?"
"It's about the Element Bearers."
"Oh. Has there been a letter from Spike that I missed?"
"No, but – you asked me to keep an eye on them tonight, as best as I was able..."
"Mm. I recall."
"I've been dreamwalking, trying to get a look in on them... Something's wrong, Tia. I... This has never happened before."
"What is it?"
"Ordinarily, I should say either that they weren't actually asleep or that they simply weren't dreaming, but this is different. I can feel the presence of their dreams, but I can't reach even one of them. There's no trace of a pathway into them. I've tried everything I can think of, but I still have yet to find a way in – it's as though I've just been cut off."
"...I see."
"Should I keep trying?"
"Yes, for heaven's sake, yes! – Where's my pen?"
Spike:
Forget everything I said. I am coming over NOW. I'll explain when I get there.
Yours, Celestia
This chapter is short, but it delivers.