Kim Manners thus urged McCrane to perform with "emotional conviction." Manners later explained that "I found that if you take the absurd and base it in the reality of human emotion, the audience is going to buy it as if it actually exists. You know?" Actor Bill Dow also appears in the episode, reprising his character Chuck Burks. The show's design staff made extensive use of makeup to give McCrane the right look; applying all the makeup reportedly took "several hours". McCrane's eyes were also augmented with specially-made contact lenses. Many of McCrane's scenes were physically exerting, such as the autopsy scene, which required McCrane to stick his head through a discreet hole in the set's mock dissection table. McCrane then held still, thereby giving the illusion that his head was severed and resting on the table. The scene in the bathtub required McCrane to spend several "long minutes" underwater motionless in full makeup. The shot in which a new Betts emerges from the old one's mouth was created by Toby Lindala. Lindala intercut shots of McCrane with shots of a specially-designed puppet that had a full-functioning mouth and eyes. Laverne Basham and Lindala were later both nominated for an Emmy for Outstanding Makeup in a Series for their roles in this episode. Academic analysis Themes According to Jan Delasara, one of the major themes of "Leonard Betts" is the exploration of "irresistible physical drives." Delasara argues that in Betts's case, his desire to kill is due to a biological need, not a malevolent desire to murder. The A.V. Clubs Emily VanDerWerff agrees, writing in her review of the episode, "It also helps that Leonard's such an understandably human monster. On some level, he just wants to survive, and he's not happy about what he has to do to be able to survive." Conversely, Amy Donaldson, in her book We Want to Believe argues that Betts's condition, in which he is "riddled with cancer" but can "see the sickness within people", is a metaphor for someone who "has let sin or evil become the regular course of life". Although Betts can detect and consume the illness, his motives are derived from "his own self appetite". Donaldson contrasts him with the soul eater, from eight season entry "The Gift". In the episode, Agent John Doggett, played by Robert Patrick, stumbles upon a creature that altruistically absorbs the diseases and ailments of