Eris has been the student of Luna and element of Harmony for only a year or so, enjoying a new adventurous life in the long cycle of death and rebirth she is used to. But a ghost from the far flung past, Luna's once sister who Eris broke, has escaped her stony prison and seeks to return the favor.

A sequel to Seconds to Spare, the most apparent role-swap involved here is between "Discord" and Celestia, here Eris and Mirage. But in the previous story it was also revealed that Luna has taken Celestia's spot, Starswirl the Bearded took Luna/Nightmare Moon's spot, and all of the elements of harmony took alternate ponies.