The Crystal Caverns are one of the only cave systems Celestia has the time to explore due to it being directly under Canterlot. Over the centuries, she has explored the caverns solely to help pass the time until her sister returns from the moon. However, she comes across a large pit where she knew there used to be a large pool of water. A crumbling stone edge later, she finds herself at the bottom of a pit full of things, things that want to touch her in places.

In case you can't guess from the title and description, this story contains crystal consentacles. Crysentacles? Either way, Celestia gets rutted by magical tentacles made out of crystals.