Comic Book Location Reference: When interrogating Matt Istook on the train track, Oliver mentions that the oncoming train's destination is Blüdhaven, a neighboring municipality to Gotham, and the city which is patrolled by Nightwing. Nightwing is the persona created by Dick Grayson after leaving the role of Batman's sidekick Robin.
Iron Heights is referenced. In the DC Comics Universe, Iron Heights Penitentiary is a maximum-security prison in which are incarcerated the many villains of the Flash's "Rogues Gallery". It also featured heavily in The Flash (2014).
John Barrowman first appeared in Honor Thy Father (2012) but was uncredited, largely hidden. This is his first credited and open appearance.
This episode marks the first time Oliver uses a device to disguise his voice.
The overhead shots of Iron Heights Prison are actually photos of San Quenten State Penitentiary in San Quentin, then CA.