- 1 Major characters
- 2 Supporting characters
- 3 Minor characters
A twenty-three-year-old Boston resident and recent widow; unbeknownst to Olivia, her father was a member of the LaPaglia Family, a Mafia entity in the area. After losing her fiancé to breast cancer, Olivia has spent a year in mourning and depression. As she finds herself at the heart of a supernatural conspiracy, Olivia discovers a commanding attitude and a host of paranormal abilities within herself.
A former Marine and paranormal investigator for Seventh Circle, Mark Tenant battled Erogrendel in the past after it killed his friends and has spent the following decade preparing himself for its return.
A grizzled detective with the Boston Police Department, Parry finds himself paranoid that he's being sidelined by his superiors. When he is assigned the Scott Roby murder case, Parry encounters Mark Tenant and Seventh Circle, who he always considered an annoyance; however, he begins to side with them as all evidence points towards a Illuminati conspiracy.
Xavier Collin Potts
A mysterious figure high within the ranks of the shadow government, Xavier manipulates North Atlantic Power as well as the police department to get his way. He apparently understands more about the supernatural than anyone else, including Kurt Bachman and Mark Tenant; he even appears to have a good understanding of Erogrendel's identity and purpose.
A young, self-assured police detective, Brannon Cox insists on doing things by the books, and as commanded by his captain; this leads him into conflict with Isaac Parry, the detective who trained him, as Brannon comes to believe Parry is losing his edge.
Originally from Berlin, Kurt Bachman is the founder and "regional director" of Seventh Circle. Long ago, he dedicated his life to uncovering the supernatural, and was quick to take on Mark as an employee after hearing his story of fighting Erogrendel.
A Midwestern farmer, Dana lost her husband and daughter nine years ago when they were killed by Erogrendel. She has become a local legend around Rutson, Nebraska, as her depression and reclusivity lead her to appear unsociable.
A young, hotheaded Rutsonite, Steve Farman spends his days getting into trouble and bullying his little brother. When Olivia and Mark come to town, Steve is immediately smitten with Olivia and pursues her romantically, not knowing about the trouble she's in.
The sixteen-year-old brother of Steve Farman, Jimmy aspires to be his brother, while simultaneously disliking him. He is attracted to Poppy Adams, though he considers her difficult. Later, he finds himself attracted to Olivia Cambridge and rescues Mark Tenant.
A wild and obnoxious Rutsonite, Poppy attends Rutson High School along with Jimmy Farman. She frequently has sex with Steve Farman (older by several years) and finds herself jealous of Olivia, despite eschewing sentimentality.
A young professional and employee at North Atlantic Power (a company owned by his father), Scott was known for harassing women at work and having them fired when they didn't comply. Scott formed a bet with his friends that he could sleep with Olivia (who they saw around the neighborhood) before them, eventually leading to his death at the hands of Erogrendel.
The mother of Olivia Cambridge and wife of Joel Cambridge, Emma Cambridge née Nole slipped into alcoholism after her husband's disappearance, but has since been able to remain sober, making up for Olivia's bleak childhood with an overprotective attitude.
The father of Olivia Cambridge and husband of Emma Nole, Joel's mother was the sister of Roberto LaPaglia, head of the LaPaglia crime family. Because of this, Joel was allowed to join in their lifestyle, but was unable to take the Mafia oath due to his half-Swedish blood. Joel's reincarnation into Erogrendel (to protect Olivia from Scott Roby and later Mark Tenant) provides the catalyst for the novel's plot.
Captain of the Boston Police Department District A-1/A-15, Melvin Cobb is a no-nonsense leader who believes Isaac Parry is losing his edge, and tries to quietly push him to the side.
A young detective with the Boston Police Department, Hardy is more laid-back than Brannon and considers Parry a friend. Hardy is the only police officer Parry trusts with his information uncovered about the shadow government.
One of only three employees at Seventh Circle (along with Mark Tenant and Carol), Ruby Lloyd is fun-loving and flirtatious, but generally disinterested in her work.
The daughter of Dana and Andrew Holman, Lilian was killed in 2006 when Mark Tenant accidentally shot her, intending to kill Erogrendel. Unbeknownst to Mark and Dana, Lilian herself had summoned Erogrendel to kill her stepfather, Ronan Matthews, who had been molesting her.
A Midwestern farmer and the second husband of Dana Holman, Ronan was a heavy drinker who molested his stepdaughter, Lilian Holman, unbeknownst to her mother. He was killed by Erogrendel, possessed by the soul of Andrew Holman, in 2006.
A nosey reporter constantly following Isaac Parry, Díaz is later revealed to be a member of the shadow government meant to screen Parry for possible employment.
An agent of the shadow government who, along with George Farman, was stationed in Rutson, Nebraska, following the 2006 appearance of Erogrendel. Unlike George, Frank appears borderline psychotic and desperate to improve his situation, apparently with the intention of someday replacing Xavier Collin Potts. Frank is the biological father of Poppy Adams and the adoptive father of several more children.
An agent of the shadow government who, along with Frank Adams, was stationed in Rutson, Nebraska, following the 2006 appearance of Erogrendel. George is the father of Steve and Jimmy Farman.
- Rutson, Nebraska
- Barney – The manager and possible owner of the Rutson Food & Supplies, Steve Farman's boss and apparently an alcoholic.
- Jim Benson – The owner of a gas station in Rutson, Nebraska – formerly a Shell station, though Benson hasn't taken down the Shell logo due to a bad knee.
- Cooper – A friend and peer of Steve Farman's, Cooper often spends his time with the younger Jimmy Farman and Poppy Adams. He is obnoxious and uncaring, though apparently affronted by Olivia's insinuations about Rutson's smallmindedness.
- Reverend Dave – A preacher in 2006 Rutson, Nebraska.
- Mrs. Revrend Dave – A schoolteacher in 2006 Rutson, Nebraska, presumably the wife of Reverend Dave.
- Garry – A mechanic in Rutson.
- Andrew Holman – The first husband of Dana Holman and biological father of Lilian Holman, Andrew died when Lilian was young and later came back as Erogrendel to kill her stepfather, Ronan Matthews.
- Madge Hooper – A Rutson resident who purchased Mark Tenant's Chevrolet Chevelle from Dana Holman, and later sold it to George Farman.
- Old Man Jacobs – A now-deceased Rutsonite, the original farmer and owner of the Holman farm.
- Martha Mageson – An unseen but often-referenced chicken farmer in Rutson.
- Mrs. Quick – A middle school math teacher in Rutson who gives Poppy Adams a ride home after a party.
- Four elderly Rutson men, known for sitting outside the barber shop and playing cards. They are introduced in the novel's prologue, and later give directions to Olivia.
- Elderly woman who owns Rutson's second-hand store.
- The elderly, senile father of the gun store owner who recognizes Mark as the last person to see Ronan and Lilian alive.
- Several adopted children of Frank Adams, adopted siblings to Poppy Adams, apparently used as part of his cover in Rutson.
- A dark-haired teenage girl who works at the Rutson Food & Supplies. According to Olivia's sixth sense, the girl has an unrequieted crush on a boy she dances with at the sock hop.
- The grandson of the Rutson second-hand store owner. According to Olivia's sixth sense, he is a closeted homosexual.
- A Rutson firefighter who is distant cousins to the Toothpick man.
- Boston, Massachusetts
- Doctor Briggs – A young autopsy doctor at Massachusetts General, Briggs assists Doctor Trope with Scott Roby's autopsy.
- Carol – The disinterested receptionist for Seventh Circle, Carol apparently escaped the shadow government after Seventh Circle burned down.
- Robert Noran – A doctor at Massachusetts General Hospital, Robert Noran was assigned to examine Olivia after her assault. Robert Noran would later appear as a supporting character in Quantum Flight 888, set eight months after Erogrendel.
- Rennie – A fellow recovering alcoholic Emma Cambridge meets at a North End pub and ends up going home with, leaving the path open for Olivia's assault.
- Vinny – The Millennial bartender at the Inferno Club, Vinny often has long conversations with Isaac Parry. Vinny is shown to believe in the supernatural, and has tattoos inspired by Star Wars and Harry Potter.
- Jonathan Trope – Head crime scene investigator with Massachusetts General Hospital, Doctor Jonathan Trope performed Scott Roby's autopsy.
- Family and associates of Olivia Cambridge
- Unnamed Swedish father of Joel Cambridge, brother-in-law of Roberto LaPaglia.
- Marissa – Olivia Cambridge's college roommate, Marissa was known to be a stereotypical hippie student, smoking weed and hanging Buddhist tapestries in their dorm room.
- LaPaglia Family
- Roberto LaPaglia – The late boss of the LaPaglia crime family, Joel Cambridge's maternal uncle.
- The unnamed mother of Joel Cambridge, sister of family boss Roberto LaPaglia.
- Johnny Bonetti, Jr. – A member of the LaPaglia crime family who killed Joel Cambridge after the death of his uncle, boss Roberto LaPaglia. By the time of the novel, Johnny Bonetti has become a caporegime under acting boss Salvator dePaola.
- Salvator dePaola – Acting boss of the LaPaglia Family after the death of Roberto LaPaglia.
- Family and associates of Mark Tenant
- Jordon – A friend of Mark Tenant's from high school, Jordon encouraged Mark to resume his debaucherous lifestyle after returning from boot camp, leading to his disillusionment with the military.
- Agnes Tenant – The mother of Mark Tenant, Agnes was known to brag about her Marine son, until she realized he had begun partying every night.
- Keona Tenant – The laid-back father of Mark Tenant, Keona recognized his son's debaucherous intentions and tried to cheerfully steer him on the right path.
- Several female Aquinas College students who partied with Mark Tenant and his friend Jordon after Mark returned from boot camp.
- Superior officer physically assaulted by Mark Tenant, leading to his dishonorable discharge.
- Family and associates of Scott Roby
- Devin – A friend and coworker of Scott Roby and Scott Jr, Devin was more hesitant to admit Scott's wrongdoings to the police.
- Elana Roby – The mother of Scott Roby, Julianne Roby, and Todd Roby, as well as the wife of James Roby, Elana is an intense woman used to getting her way.
- James Roby – The father of Scott Roby, Julianne Roby, and Todd Roby, as well as the husband of Elana Roby, James Roby is a Harvard graduate and the owner of North Atlantic Power. He is apparently in bed with the shadow government, as he takes direct orders from Xavier Collin Potts concerning his son's case.
- Julianne Roby – The eighteen-year-old sister of Scott Roby, a freshman at New York University.
- Todd Roby – The eleven-year-old brother of Scott Roby, Todd is known to have "unusual hobbies."
- Scott Jr. – A friend and coworker of Devin and Scott Roby, this Scott was referred to as "Scott Jr." so as to differentiate the two.
- Janet – A coworker of Scott Roby, Scott Jr, and Devin, Janet was a target of Roby's, and was allegedly fired after she refused his advances.
- The unnamed priest at Scott Roby's funeral who reads from the Book of Sirichai rather than from the Bible.
- The gravediggers at Scott Roby's funeral.
- Family and associates of Isaac Parry
- Virginia Parry – The ex-wife of Isaac Parry, Virginia is never seen in the novel, but is heard when Parry desperately calls her on the phone.
- Isaac Parry's unnamed sister, who likes to remind him how well he fits the "grizzled detective" archetype.
- House – Isaac Parry's gray house cat, whose name and origin remain a mystery.
- Officer Barrett – A Boston beat cop assigned to door-to-door duty surrounding the Roby case.
- Detective Darrow – A detective with the Boston Police Department, Darrow is pulled off his assignment concerning meth distribution and assigned to help Parry and Brannon on the Roby case.
- Officer Herard – A Boston beat cop assigned to door-to-door duty surrounding the Roby case.
- Officer Michael Hunt – A Phoenix officer who discovered Randy Jacobson's body while off-duty in 1990.
- Detective Johnson – Darrow's partner on the meth case, Johnson is on stand-by to aid in the Roby case.
- Officer Lockard – A Boston beat cop assigned to door-to-door duty surrounding the Roby case.
- Officer Nader – A Boston beat cop assigned to door-to-door duty surrounding the Roby case.
- Detective Ryan – Hardy Lee's partner on the case of an old man's murder outside Fanieul Hall.
- Officer Hudson Q. Sentree – A New York officer who discovered David McCallaster's body in 1955.
- Erogrendel cult
- Toothpick man – The owner of Rutson's firearms store, later revealed to be part of the cult that reveres Erogrendel.
- MAGA man – A member of the Rutson cult that reveres Erogrendel, known for wearing a Make America Great Again hat.
- An unnamed young, fit man wielding a baseball bat.
- An unnamed cultist tasked with pistol-whipping Mark Tenant into unconsciousness.
- Shadow government
- Darius Torne – A technology expert under Xavier, later in a relationship with Ruby Lloyd.
- Agar – A former military man, now a commander of sorts in the shadow government.
- An unnamed African-American agent tasked with taking Olivia Cambridge to the facility cafeteria.
- Odilia – A young Danish woman who summons Erogrendel to kill Hrothgar.
- Hrothgar – A character appearing in the epic poem Beowulf, Hrothgar appears in Erogrendel as a fat and salacious lord who rapes Odilia after she is given to his care.
- Doubly fictional characters
- James Tannen – Protagonist of Sirichai Jones's The Mist of Time whose story arc revolves around his unrequieted love for Elizabeth Marlowe.
- Elizabeth Marlowe – Primary love interest of Sirichai Jones's The Mist of Time, Elizabeth Marlowe spends the novel rejecting James Tannen, only to realize she loves him near the end and be rejected herself.
- Randy Jacobson – A young man living in 1990 Phoenix, Randy Jacobson was killed by Erogrendel after a string of other deaths.
- David McCallaster – A man living in 1950s New York City, David McCallaster was sent to prison for beating his wife. In 1955 he escaped, but was immediately killed by Erogrendel.