Father Callahan is the local Roman Catholic priest of the small Maine town of Jerusalem's Lot. Callahan presides over the funeral of Danny Glick, a young boy who was, unbeknownst to the townfolk, killed by a vampire. Life goes on as normal, until more and more of the populace disappear and are turned to vampires. Ben Mears, a local writer, discovers the epidemic that has been propagating during the nighttime. Joined by his girlfriend Susan Norton, local teacher Matt Burke, doctor Jimmy Cody, and the young Mark Petrie, he convinces Callahan of the Vampire presence and enlists him to help.
Unfortunately, while making an attempt to slay the "King" Vampire Kurt Barlow, Susan is captured and bitten. Callahan leads a daytime assault to Barlow's manor, which the vampire had vacated in anticipation of their attack. However, the group uses the opportunity to slay the vampiric Susan as well as to purify the house against future vampire occupation.
His faith falters in the presence of the leader of the vampires in Jerusalem's Lot, Kurt Barlow. After saving Mark Petrie from the vampire, his faith fails and he is dependent on his crucifix, which soon loses its powers. Barlow tears open his own throat and forces the priest to drink his blood, taunting him by calling him 'shaman' and ultimately damning him.
Defeated, Callahan returns to his church, but burns his hand on the door and is refused entrance. Callahan leaves the town on a bus, bemoaning how 'unclean' he has become.
After fleeing the Lot, Callahan arrives in New York City, and becomes a vagrant. Now able to sense vampires, he realizes that they live and hunt all around him. His alcoholism gets worse but after he starts working at a homeless shelter, he begins to recover. He befriends several people, such as Rowan Magruder and Lupe Delgado. Callahan later develops a deep fondness for Lupe and later admits to having fallen in love with him. He wonders if this means he is gay, but despite a brief kiss on the cheek, nothing physical occurs between them.
Callahan learns that there are three types of vampires. The Type Ones are the most powerful ones and are almost immortal. They can spread vampirism to others and create Type Two vampires. Kurt Barlow was a Type One. Type Twos are more common and can create other Type Twos or Type Threes. Lastly, the Type Threes cannot spread vampirism but can spread diseases that travel by blood, such as HIV. Callahan refers to them as 'mosquitoes'. After Lupe is infected by a Type Three vampire and dies from AIDS, Callahan begins to kill vampires (mostly Type Threes). This attracts the attention of the Crimson King and his soldiers, the Low Men or "can-toi". The Hitler Brothers, two hoodlums who murder Jews, black people and homosexuals, and carve swastikas on their victim's foreheads, are hired to find Callahan. They torture Rowan Magruder, who later dies of his wounds, in hopes of finding him.
They later find and attack Callahan, and carve a cross on his forehead, intending it to become a swastika. But before they can finish the swastika, Callahan is rescued by Calvin Tower and Aaron Deepneau, two men who figure prominently later in Roland's quest. The Hitler Brothers flee, and are later killed by the Low Men. Callahan is later lured into a building by Richard Sayre, a Low Man, and several vampires. Rather than being infected, he jumps out a window, committing suicide.
After his death, he wakes up in the Way Station, where he encounters Walter o'Dim who gives him Black Thirteen, one of the "Bends" in the Wizard's Rainbow. Walter apparently does so in the hopes that it will kill Roland Deschain later in his journey. It transports him to the Doorway Cave outside Calla Bryn Sturgis, where he leads a new life and over the next five years attempts to teach the locals his religion.
Roughly every twenty-three years, the Callas are raided by Wolves, which turn out to be robotic soldiers serving the Crimson King. These Wolves steal half of the Calla's children, who return a few months later "roont". "Roont" (ruined) children are sterile, mentally handicapped, grow to be larger and stronger than other children, and die painfully at a younger age. When Roland and his ka-tet arrive, Callahan seeks their help to defeat the Wolves. During their stay, he shares with them his story since the events of Salem's Lot. The Wolves are defeated with the help of the ka-tet, but Susannah becomes possessed by the demon succubus known as Mia and escapes via the Doorway Cave. There, Callahan discovers a copy of the novel Salem's Lot, written by Stephen King, in which he is a major character, causing him to question his reality.
The ka-tet regroups in Callahan's house, where they lay down their plans of action; Roland and Eddie would follow Susannah to New York while Jake and Callahan would be sent to Maine, in order to visit Calvin Tower (the man who saved Callahan from the Hitler Brothers) as well as Stephen King, in order to ensure that the remaining books are written. While there, Callahan planned on questioning King about his existence, but something goes wrong when the door is opened. The group is uncontrollably sucked through and separated, with Roland and Eddie ending up in Maine and Jake, Callahan, and Oy landing in New York City in the year 1999.
The trio lands violently in the middle of a busy street, and Oy is very nearly run down by a speeding cab. Preventing a potentially deadly response from an angry Jake, Callahan beats down the aggressive driver and bribes him (before Jake had the opportunity to shoot him), and they remove themselves from the scene.
Thanks to Jake's psychic connection with Susannah, they find the hotel where Susannah/Mia left Black Thirteen. They attempt to remove it safely, but it awakens and forces them both to their knees, urging them to murder each other. They nearly succumb to the suicidal whisperings, but Callahan uses his restored faith to silence the orb, putting it back into its slumber and saving their lives.
In search of a safe storage place, he and Jake move Black Thirteen to a long-term storage locker underneath the World Trade Center, with the hope that either it will stay dormant or Roland will at some point come to destroy it. (Rather aptly, they comment on how a building falling on it might destroy it, foreshadowing that the future terrorist attack will be the end of the crystal ball.)
They go to the Dixie Pig, the restaurant stronghold of the Low Men and vampires where Susannah is being held, where they prepare to ambush the unknown forces within. Jake and Callahan burst into the Dixie Pig, where they are greeted by a preponderance of Low Men and lesser vampires, as well as a gathering of "Type One" vampires (of which there are only a small number in existence).
Seeing the overwhelming odds against them, Callahan sends Jake on ahead to rescue Susannah while he draws their attention. After dispatching several Low Men and Type Ones, he is goaded to toss away both his cross and the sigul of the turtle (the magical ornament that incapacitates the Low Men). At this point Callahan realizes what he did not understand while facing Barlow in 'Salem's Lot; the power of his faith transcends such objects.
Eventually, once Jake reaches relative safety, he's overwhelmed and swarmed by the vampires. Before the beasts can assault him, he once again escapes their clutches by shooting himself under the chin. Before taking his own life, he converses briefly with Roland, who bears witness to the scene across time and space. His final words to Roland and in life were a benediction to the Gunslinger: "May you find your Tower, Roland, and breach it, ...and may you climb to the top!"
Jake in particular was disturbed by his death, and the ka-tet mourned the loss of their friend and compatriot. When Roland finally made it to the Dark Tower, Callahan's is one of the names shouted by Roland as he walks through the field of roses, showing Roland's respect and love for the redeemed Priest.
Roadwork (Richard Bachman)
Though not officially connected to The Dark Tower; Phil Drake is in fact Father Callahan in the book Roadwork . He is a fallen priest who helps the homeless and has left "The mother church." He will not allow himself to be called father and has a "oddly scarred right (hand.)" As this book is not highlighted as a connected book, it seems that King himself was not even aware that in 1981 he was bringing a character back from a 1975 novel, and even stranger the character is much more like what he has become by 2004.
The original draft of Salem's Lot originally depicted a different fate for Callahan. Rather than forced to drink Barlow's blood and leaving town damned, he marks the vampire with a knife before committing suicide. Furious, the vampire desecrates the priest's body, decapitating it and hanging it upside down. This scene was changed by King before he originally published the story, though it was included in a section of deleted scenes featured in the deluxe limited edition released by Centipede Press in 2005 and the later trade edition.
In the miniseries, Father Callahan is featured only as a minor character. He is played by James Gallery. Callahan is first briefly seen officiating at the funeral of Danny Glick. Later, Ben Mears and Susan Norton have a brief interview with him where they try to convince him to join them against the evil in the town. Callahan is skeptical and makes a brief comment on how the Church's view of evil has changed. Soon afterwards, Callahan is at the Petrie house to talk to Mark and his parents about Mark's nocturnal experiences. Abruptly, with a surge of electricity and a tremor, the vampire Barlow enters, kills the Petrie parents, seizes Mark and challenges Callahan. The exchange, although shortened, is much the same as in the original novel, only with Straker, now also present, interpreting for the more monstrous and less articulate Barlow. Barlow lets Mark go in order to confront Callahan, who falteringly hold on to his crucifix while facing the vampire. Barlow plucks the Crucifix from the priest's hand, and Callahan is not seen again, presumably killed.
1995 radio drama
In the (1995) BBC radio-dramatization of the 'Salem's Lot novel, Callahan was voiced and played by Nigel Anthony.
In the 2004 miniseries, Father Callahan was portrayed by James Cromwell. The beginning of the film shows an event taking place after most of the story; Ben Mears enters a homeless shelter and sees Callahan giving out food.
Mears confronts Callahan and chases him up some stairs where they struggle. Mears pushes Callahan out a window; the two of them land on a police car. The rest of the film is told in flashback as Ben explains to a hospital orderly why he attacked Callahan.
Callahan is generally portrayed as in the novel (although there is a scene with him browsing what could be a Satanic porn site), but after Barlow forces him to drink his blood, Callahan does not leave town in shame. Instead, he takes Straker's place as Barlow's slave. Callahan later visits Matt Burke in the hospital and impales him with his cane.
As Ben Mears tells his story to the orderly, Callahan is suffocated with a pillow by Mark Petrie in the hospital.
These events contradict the last three Dark Tower books, which feature the return and redemption of Callahan.
Callahan was a tall man with piercing blue eyes and a ruddy complexion. His hair was a graying steel color. He had many red and broken veins in his cheeks and around his nose from drinking.