Ward Captain Leo Ramutka enters his home after a wake and is greeted by an armored figure that fires a crossbow at him, killing him and literally pinning him to his front door.
Carl hears in the police radio and goes to Ramutka's house, where he hears that "legend" Captain Vernon Rausch is in charge of the investigation. Carl gets some basic information from the overly-chatty Rausch, including the fact a crossbow was the murder weapon, but is soon lost in the Captain's meandering dialogue.
The next night, 10:20. Rolf Danver, real estate developer, is driving home and pulls into his driveway when the same armored figure appears before him and impales him through his front windshield with a jousting lance.
In a press conference Rausch denies a connection between the murders, and Carl gets another reporter to ask a question as a distraction to get into Rausch's office and ask him a few private questions. Rausch (eventually) reveals Danvers was killed with an ice pick…with a three-inch diameter. Carl believes the murders are related despite Rausch's (vague) denials. Carl then goes to see his contact Pop Stenvold, a pawnshop owner and weapon expert. Stenvold offers to identify the arrow in return for Carl documenting his long, boring biography. The arrow is a bolt from a medieval crossbow that would require 300 psi to crank and would be impossible to find in the modern-day. Pop reveals he's in a foul mood because of a social security worker and refuses to take money from Carl – he'd rather have Carl do the biography.
Thursday night, Brewster Hocking, owner of the Canadian-American Leisure Corporation, is at home in bed when he hears a clanking noise outside and calls for his butler Charles. What comes in is an armored figure bearing a chained mace which steps on a phone then crushes in Hocking's skull.
At the Hydecker Museum, devoted to medieval antiquities, Carl arrives seeking information as the caretaker Mendel Boggs is fighting with decorator Minerva Musso. Minerva makes her exit and Boggs reveals how a soda pop company is turning the museum into a discothèque and taken away much of the collection. Boggs is dismissive of the picture's quality but identifies it as a medieval crossbow bolt. Carl notices that one suit of armor has a nearby empty quiver, and that there is a crossbow capable of firing the bolts on the wall. He also spots a mace.
At the morgue, Carl checks up on Brewster Hocking and the attendant reveals nobody can make out what killed Hocking, but Carl suspects that a mace was responsible. The next day, Carl gets a fake telegraph made up and goes to speak with Hocking's butler Charles Johnson. Carl claims Hocking contacted him and they're fraternal brothers. Carl manages to get to the bedroom and spots the smashed phone. Carl's bluff falls through and he gets out.
At the INS office, Carl wrecks his own phone to get a telephone repairman in since the company won't return his calls about how much pressure it would take to destroy a phone. It takes 420 psi but the repairman realizes Carl sabotaged his own phone and then starts pulling out various unauthorized bootleg phones, much to Tony's dismay. Carl reveals that he suspects Mendel Boggs since Hocking was tied in with the company that was buying the Hydecker. He goes to see Minerva in her apartment and after some initial confusion Carl gets to the point about the Hydecker Museum. Minerva reveals that Boggs speaks poetry to the suits of armor and waves weaponry around when he's alone. She doesn't know Hocking but they're interrupted by a clanking noise. Carl goes out and sees the armored knight bust in. He locks the door and tries to barricade it but is casually knocked aside into unconsciousness, covered in perfume. The knight goes into the bathroom and cuts Minerva in half with a battle axe.
As Minerva is taken out, Rausch proceeds to interrogate the injured Carl and tries to negotiate by giving Carl an exclusive. Carl figures out Rausch doesn't investigate but just gets information from contacts and newspapermen, but has no choice but to tell Rausch that a knight killed Minerva. Carl reluctantly tells Rausch his theory about Boggs. They go to the museum and Boggs denies everything. The weapons are clean and the suit that Carl saw, which is at the museum, doesn't fit Boggs. Rausch apologies to Boggs and leaves, but Carl talks to an angry Boggs. The armor belonged to a Black Cross knight but Boggs refuses to say anything further.
Carl goes to visit a mom-and-pop Coat of Arms business and they try to sell him on buying a distinguished Kolchak crest. Carl is more interested in tracking down the heraldry of the shield he saw at the museum. The man identifies the heraldry as belonging to the Mettancoeur family of Burgandy. The last of the line, the Guy de Mettancoeur, ducked the crusades and amassed a fortune by killing women and children. Although his family dealt in wine, Guy hated human pleasures and become a pariah in his own time. Mettancoeur consorted with reputed wizards and had a reputation for invincibility. Carl goes through the book and confirms the armor Mettancoeur wore is the same as at the museum.
Carl confirms that Hocking handled the Mettancoeur wine, then explains to Vincenzo that Guy had an invulnerable suit of armor, and how he was slain by a blessed axe blessed by Pope Gregory – the axe is at the museum as well. With his last breath, Guy swore that music and human gaiety would never disturb his resting place. Brewster and Minerva were responsible for turning the Hydecker into a discothèque, and Ramutka and Danvers were dealing with the land issues. Carl heads out declaring he's going to get the story at the Hydecker come hell or high water.
Carl breaks into the Hydecker and starts taking photos as he finds the Mettancoeur armor is gone. He hears a clanking noise and takes cover as the animated armor comes walking down the stairs. After it walks by, Carl starts snapping photos, which naturally it notices. It picks up a javelin and Carl ducks barely in time. Then the armor grabs a sword and goes after Carl, who tries to grab a sword. Failing, eh plays duck-around-the-table, trips, and goes flying. He manages to get to the case holding the blessed axe although the knight steps on his camera. Carl throws another suit of armor at it long enough to get the axe out. The suit cowers back and Carl manages to lift the monstrosity enough to get in one good blow, then plant it on the ground so the knight falls directly on it. Carl is left to consider all the explanations he's going to have to make.