When Ruby boards the first trans-oceanic flight in Equestrian history, the last place she expects to end up is stranded in the middle of Eternity's Crossing in the wake of a horrific zeppelin crash. After a mysterious tower leads her and a fellow survivor to discover a twisted and fragmented city twenty thousand feet below the surface of the ocean, though, a bit of fire and smoke is the last thing she needs to worry about. Between the horrendously disfigured residents and the paranoia of the madmare who once built and controlled it, daily survival in this corrupted utopia is anything but a guarantee. But with the help of some new friends and a few genetic enhancements, Ruby isn't going down without a fight, and in the process might just discover that the deadliest weapon in Harmony is herself.

An adaptation of BioShock for the world of MLP. Written to be comprehensible to anyone, regardless of whether they've played the original game.