 Paul Birchard was cast as Libby McCall because the producers believed he acted like a "dinosaur" from the former Bush administration. Child actor Luke Tzortzis was cast as Nico since they were impressed with his intelligence and the fact he is a "strong" actor; children are often hard to work with in the series, but in Tzortzis'case, he would ask the production crew several questions between takes in order to do understand what he is to do in the episode. It was also Tzortzis' first performance as an actor, having no past experiences.
