Justice League:Return of the Justice Lords is a 2007 animated superhero film. It takes place between Justice League and Justice League Unlimited. It is in continuity of the DC animated universe.
The Justice Lords has returned and imprison Supergirl in their dimension as the Justice League must fight their parallel counterparts again to save her.
The hospital where Supergirl was being held at is the same one where the original founding members of the Justice League were imprisoned.