Three in a Hole

The Princesses are trapped in Tartarus by Tirek.

Celestia, Luna, and Cadence have to keep their hopes high and belief in Twilight higher. This is what happens when they're left powerless in a prison with nothing more than each other's company.

Prereaders
Flint Spark
RK_Sriker_JK_5
Guy_Incognito
DumdoDoor