Originally scheduled to be released in the fourth season, despite a couple clips appearing in the sizzle reel for that season, this webisode was moved to Season 5 to coincide with Mera's appearance in Aquaman at the time the film was first set for a July 27 theatrical release, later October 5 until it was delayed again to December 21. In addition, this webisode marks the last to be written by Shea Fontana.
The title references Supergirl's location. But unlike its comic book counterpart that's placed inside of a icositetrahedro, the DC Super Hero Girls version of the Fortress of Solidarity bears a resemblance to the famous Superman location Fortress of Solitude, only at the North Pole instead of the South.
This webisode marks the third Season 5 webisode to air both parts together. Had it aired in the previous season, it would've been released as the two-part season finale.