Haly's Circus - Batman: The Dark Knight

While Haly’s Circus brought joy to thousands across America, it concealed a dark secret known only to a select few: it served as a recruitment front for the Court of Owls, grooming young performers to become their Talons.

Ringmasters acted as drill sergeants, pushing candidates to their absolute limits—only the best were deemed worthy of the Court.

As of 2012, and the Night of Owls, this practice was still ongoing.