Shepherd Book

Glass, a veteran actor well known for his role as Detective Ron Harris in the television sitcom Barney Miller, had rarely tackled the science-fiction genre and was hesitant about this role when his agent approached him. However, once he read the script he "...fell in love with it".[3] As Glass noted:

"The thing that was galvanizing for me was the characters, so the environment was secondary. I was happy to see how Book would unfold in that kind of environment and it worked really, really well."[3]

Glass stated that Whedon and the costume designer Shawna Trpcic "had a pretty clear idea of how they wanted him to look", and how he appears in the pilot with a distinctly priestly collar and scant possessions "was a strong reflection of the character".[3] For the role in the film Serenity, Trpcic decided to make Book's clothing tighter after seeing his physique.

Book's character during the series is a preacher, and though Glass discussed with Whedon about making him more Buddhist, Whedon explained that the character of Inara Serra was to be the Buddhist-type and Book more of the "fundamentalist Christian guy".[3][4] Glass, himself a Buddhist, found it intriguing to play this role:

"What I was able to bring to the Christian part of it was the humanism and the humanistic point of view. It was the hook in terms of being able to make that adjustment. I wasn't born Buddhist, so I do have some other traditions to pull from."

— Ron Glass[3]

Whedon conceived the character because he felt that faith was important to people dealing with being that far out in space. As Whedon states, "Shepherd Book is somebody I would probably get along famously with, except we don't agree about anything." He also wanted to give "a voice for the other side".[5]

One of the underlying aspects of the show is Shepherd Book's secret past. He holds some sort of high priority status within the Alliance, and on numerous occasions has demonstrated a depth of knowledge in a number of fields one would not expect a clergyman to be familiar with, including space travel, firearms, hand-to-hand combat, and criminal activity. Glass enjoyed this aspect of the role as well: "Though rather mysterious, it was absolutely clear that he had had a very full life before he went off to the monastery and took on that responsibility. I loved the fact that he could save your soul but he could also kick your ass. That's a really great combination to play."[3]

In the 14th episode of Firefly, "Objects in Space", Simon berates the bounty hunter Jubal Early for assaulting Book, a Shepherd. Early replies, "That ain't a Shepherd."[6] In the DVD commentary Firefly, Whedon states this is due to Early's intuition and ability to quickly size people up. He also comments that Early's methods for dealing with each crew member are custom-tailored to their personalities. Early disposes of Mal in a straightforward manner; Whedon then notes that Early's method for taking out Book is equally straightforward, alluding to a similarity between the two otherwise different characters.[7]

Another hint to Book's mysterious past is shown in the episode "Safe". When Book is accidentally wounded, Mal is forced to seek medical help from an Alliance cruiser. The commanding officer, after tersely dismissing Mal, changes his attitude once one of his officers shows him Book's identification. Though the exact information on the card is never shown, the crew does note that it affords Book urgent and immediate access to the medical facilities on board, as well as free passage for Serenity without the expected inspection.[8] Several other episodes contain allusions to Book's past; in "The Train Job", he is aware of the identity of crime lord Adelei Niska,[9] while in "War Stories", he displays a working knowledge of high-powered weaponry, first to identify sharp-shooters and later to take part in a coordinated assault against Adelei Niska's space station.[10]

On the 2007 Browncoat Cruise, Ron Glass revealed with Whedon's permission several facts about Book, including that Derrial was not the shepherd's real name, but the name of a man he had killed.[11] Also, a "part of [him] is artificial, he found God in a bowl of soup, and [he] is best known for his greatest failure".[12] This was part of an announcement for a comic book series based on Book's past, titled The Shepherd's Tale.[11] Scott Allie, editor for the Serenity: Better Days comic series, confirmed this announcement and stated that Dark Horse Comics was aiming for a late 2008 release.[13] It was later announced that this would be seeing print in November 2010,[14] and was subsequently released November 3, 2010.[15]

During the Dallas Sci Fi Expo 2012 Ron Glass said he did not like the fact that Book had never been married, and would like to have married at some point in the show.

• Malcolm Reynolds – Glass approached the relationship with this character as a reflection of his former self. He felt that it was Book's desire to have Mal see the brighter side of himself, but knowing he could not confront him directly, he instead has to do this obliquely.[21] It was a confrontation with Mal in which Book lost his temper to the point of striking him that cemented the Shepherd's decision to leave Serenity.[19] Roger P. Ebertz states that Book and Reynolds "are opposite with regard to religion", but "they also appreciate and respect one another". He compares the relationship of the two characters to yin and yang, they "complement each other in dynamic, yet taut, harmony". And despite their opposing basic views, Book also shows doubt, while Mal "is driven to believe".[4] Eric Greene ascribed part of the fascination of Book's character to his relationship with Reynolds.[22]
• Jayne Cobb – Book has a generally friendly relationship with the normally gruff and unsophisticated Jayne. During the series, they are seen joking with one another during chores and seem to regularly lift weights together. In "The Message", they even engage in some philosophical discussion about death and people's reactions to it.
• Inara Serra – Initially, Book does not agree with Inara's work as a companion, although he is never shown as anything less than respectful of her. He even jokingly hints that he isn't anywhere near as judgmental as Mal would seem to think. At the end of the pilot episode "Serenity", Inara reassures Book when he confesses his doubts and questions to her.[17][23][4]
• Kaylee Frye – Book and Kaylee form a relatively immediate bond of friendship, as Kaylee is the crew member inviting passengers aboard in the pilot episode "Serenity", including Book (who offers her some strawberries and her reaction to them hints at their scarcity). Later in the episode, when Kaylee is recovering in the infirmary after being shot in the stomach, Book watches over her and holds her hand. In the episode "Safe", when Book is shot, Kaylee reciprocates: "He did this for me once."[24]
• River Tam – River takes a very analytical approach to religion, which Book seems to find very frustrating. He makes an attempt to explain faith to her at one point, but while intrigued by the concept, it confounds and confuses her. Another strain on their relationship comes when River "corrects" Book's copy of the Bible, as she notes it is full of self-contradictions and inconsistencies. Their relationship is further strained later when, upon attempting to broach the subject of faith again, she sees the preacher with his hair unbound – a sight which terrifies her – and after that she shows no desire to take part in future religious discussions with the Shepherd. In a later scene, he finds her editing a copy of the Bible again, but she says: "Just keep walkin', preacher man." He grimaces slightly but acquiesces, considering it a lost battle. Even so, Book asks after her well-being in a conversation with Simon (War Stories), and speaks in her defence after an incident (Objects in Space).