After the events in Storm Front, Kim Delaney, whom Dresden helped to control her magical talents, asks Dresden how to create a set of three magical circles, which could be used to contain powerful entities. Dresden withholds the information, because such circles are generally used to contain demigods and archangels. Lt. Karrin Murphy asks Dresden to consult on a homicide: a henchman of mobster Johnny Marcone was found, savaged, near a group of wolfish paw prints. Without telling Murphy, Dresden magically follows the scent of the murderer's blood that leads him to a confrontation with a gang of teenage werewolves and their pack leader, Tera West. After consultation with his oracular skull, Bob, Dresden informs Murphy of the existence of four different types of lupine theriomorphs: classic werewolves, hexenwolves, loup-garous and lycanthropes. At the police station, Dresden gets a tip from FBIAgent Harris that the Streetwolves biker gang might know something about the murder, and learns that the Streetwolves and their "pack leader," Parker, are lycanthropes. Dresden escapes unscathed, but now the Streetwolves want him dead. Marcone offers to hire Dresden for protection, but Dresden refuses. On his way out the door, Marcone says that these killings are connected to a millionaire named Harley MacFinn and his Northwest Passage Project. Dresden summons the demon Chaunzaggoroth in order to get information, exchanging one more part of his name for information about Harley MacFinn. Before Dresden can check on Harley MacFinn, Lt. Murphy arrests him on suspicion of murder: Kim Delaney's shredded body was found in MacFinn's apartment next to a summoning circle. Tera West frees Dresden, telling him that MacFinn, her fiancé, is a loup-garou, the most dangerous of the four "breeds" of werewolves. Dresden must draw a containment circle around MacFinn before the next full moon, or more innocent people will die. Dresden is shot during his escape from police custody, and is rescued by Tera. Desperate, he calls his sometime-girlfriend Susan, a reporter, and bums a ride in exchange for an exclusive on the wolf murders. Ignoring Dresden's warnings, Murphy arrests and jails MacFinn in his human form. Dresden races to the station to get to MacFinn, but the moon rises, and MacFinn changes, slaughtering the suspects in the holding cells, the desk sergeant, and Murphy's staff. Dresden drives off MacFinn and goes in search of Marcone. While searching for MacFinn, Dresden is attacked by the Streetwolves. They are interrupted by the FBI agents, and Dresden captures one, learning that the agents are hexenwolves, planning on killing Marcone and have been working with the Streetwolves, planning on using MacFinn to kill Marcone. At moonrise, Dresden, Susan, Tera and her pack drive to Marcone's estate to save him from MacFinn. Dresden and his allies are captured by the FBI hexenwolves and are thrown into a pit Marcone had prepared to capture the transformed MacFinn, but Marcone frees them. Dresden and Murphy kill the FBI hexenwolves and MacFinn, and burn the hexenwolves' talismans so they can never be used again. Susan evacuates the Alphas, and the Chicago police arrest Marcone on general principle, though Dresden predicts that no charges will be filed. Tera, revealed to be a wolf that can change into a human, accepts that MacFinn had to be killed before he could cause more deaths, and returns to her family in the Northwest.
Introduced characters
FBI Agent Phil Denton: FBI investigative team leader.
FBI Agents Deborah Benn, Roger Harris and George Wilson: Members of Denton's FBI team.
Harley MacFinn: A millionaire environmentalist with lupine qualities.
Tera West: A mysterious woman with lupine qualities and the fiancée of MacFinn.
The Alphas: A gang of college-age men and women who have werewolf abilities.
Billy Borden: One of the Alphas.
Georgia: One of the Alphas.
The Streetwolves: A Chicago biker gang of lycanthropes.
Detective Rudolph: A new officer at SI.
Reception
Thomas Wagner, on behalf of sfreviews.net praised the book, writing "This is some sick, adrenaline-charged action storytelling, spun with a Hollywood sensibility for maximum endorphin rush. No, it isn't great literature. It's great escapism, a pure roller coaster ride. There's a difference." For fantasybookreview.co.uk, Bindi Lavelle wrote "The detective stylings of Foolmoon enriches a plot full of red herrings and clues that only come together in the book's climax; Fool Moon reads like a good detective novel, with magic. For a page turning mix or neo noir and urban fantasy, look no further than Fool Moon." Victoria Strauss wrote " Butcher keeps the thrills coming, with plenty of mystery, suspense, and edge-of-your-seat action scenes." in a review on sfsite.com.
''Fool Moon'' in other media
The novel has been adapted into an eight-issue comic book mini-series, adapted by Mark Powers and illustrated by Chase Conley.
The novel was released as an audiobook, narrated by James Marsters.
Several elements of the novel were used in the episode "Hair of the Dog" of Dresden Files television series.
