[And Twilight's eyes go wide, eyes sparkling as she realizes something]

That's it! The past! Aqures Tosf! I wasn't there for it, but if I remember correctly, everyone who went to the past was stuck in a locked room where the Crystal of Fire was held, right? There was a giant hole that she fell into when some of the other heroes tried to rescue her!

That was the last time any of us saw Kalki. It could be possible that it's still down there!