Monday, September 22. Lenny Strayhan, a linebacker, is killed, his heart cut out with a dull knife. Wednesday, September 29, Staff Sergeant and Green Beret Rolf Anderson is leaving his office after hours when hears an eerie flute playing in a stairway. He goes to investigate and several costumed figures grab him, rip open his shirt, and cut out his heart.
Kolchak is at a publisher's convention at the Sherwood Hotel to help Vincenzo butter up the publishers but shows up late. Just as he gets there he hears a report of a murder at the Federal Building. Captain Webster is briefing the reporters and Carl quickly ducks aside and gets to the stairway where the coroner notices the heart is seven steps below the body on the stairs. They notice Carl and Webster takes his tape recording of the coroners. Carl notices there were multiple assailants and connects Anderson's death with that of Strayhan.
Carl returns to the Sherwood where Vincenzo introduces Carl to Tillie Jones, the PR head of the hotel, and Captain Madge Timmins with the Air Force. Tony tries to get Carl to do a story on Jones, who is supposed to be the first woman certified for combat. A Pepe Torres barges in, accompanied by three attractive women, and notices the attractive Captain Timmins. Torres is a bit of a bore and after he leaves Tillie Jones apologizes and explains he's one of the vice presidents. Carl has snuck off to avoid the speeches. Later in the hotel, Captain Timmins is preparing for bed when she hears a flute and the same costumed figures barge in.
12:30 a.m. – Carl is on the streets when he gets a report of a disturbance in Grant Park. The police arrive and find Timmins laid out on a flight of stairs, dead. Carl arrives seconds later when the police spot someone in the bush. Carl is taking photos and notices the heart lying down the stairs when a man dressed in a feathered costume comes barging through and knocks Carl to the ground. The medics wake up Carl, who managed to grab a handful of feathers from the costume. Webster interrogates him but doesn't believe Carl's (true) story of being attacked by basically a giant red-and-yellow chicken. Carl notices the connection that it's the ninth day o the murder and the heart is nine steps below the body.
Carl returns to the hotel to beat the police to Timmons' room, but they're already there. Officer Lyons, who received a medal for killing three bank robbers, keeps Carl out. Undeterred, Kolchak grabs a waiter's outfit to sneak by but Tony seems him and blows his cover. Lyons chases Carl into the basement and hides in a room marked "No Admittance." One of Pepe's women from earlier locks the door and tells Lyons there's nothing in there. Carl puts on his suit and notices a picture of a man wearing the same feathered costume as the man who assaulted him. After taking some pictures, Carl prowls around and finds a crate holding a gold sarcophagus. Inside that he finds a mummy. Breaking for the door, he finds it locked and yells for someone to let him out.
The hotel security take him to Mrs. Jones, who is meeting with Webster and Lyons. Jones refuses to press charges and Carl asks to speak with her in private. After the police leave, Carl wants to know who is in charge of the storage room and wonders what Pepe's connection is to it. Mrs. Jones finally admits off-the-record that Pepe is a dummy who keeps screwing things up, and she has to cover for him or get fired. She reveals he gets whatever he wants and that he's been there about a ear with the boss' blessing. She's interrupted before she can say anything further and Carl goes across the hallway to meet with Pepe…who is practicing the flute. Pepe introduces the three women as Nina, Lona, and Vicky, his "staff." When Carl starts to ask him about the storage room, Pepe dismisses him and he's escorted out.
Carl goes back down to the basement and makes his own entrance into the locked storage room with a fire axe. The picture and the sarcophagus are gone but Carl discovers another feather. He visits a taxidermist, Mr. Eddy, who after some initial antagonism comes around and identifies the feathers as from a parrot native to Southern Mexico. Carl asks him about mummification procedures in that area of the world and after some haggling, Mr. Eddy briefs him on Incan and Aztec mummification processes.
At the INS office, Tony contemplates the stuffed mouse Carl was forced to buy and then has to contemplate Carl's story about Aztec heart sacrifices. Carl has determined that the owner of the Sherwood hotel chain owner, Andrews, has a branch in Mexico City and were originally Argello and changes their names. The hotel chain started in Veracruz, and there were five heart murders there approximately 100 years ago, and 52 years ago there were five more murders in Atlanta, the site of their first American hotel. The police don't believe Carl, but he's hoping that Vincenzo will go to the police or at least put the story out. Vincenzo insists that Carl gets more documentation and suspects he's hallucinating. Carl takes his stuffed mouse and leaves (although not before leaving it in Ron's in-box).
Next Carl meets with the Mexican commercial attaché who is not surprisingly a bit reluctant to talk about Aztec heart sacrifices, and would rather talk about tourism, industry, and handblown glass. As he's leaving, Carl notices a picture of a Aztec headpiece similar to that on the sarcophagus, and the attaché directs him to an exhibit by Professor Rodriguez at the university.
That night in a quiet part of town, one of Pepe's women is waiting besides her car, with the hood up. Officer Lyons comes to her assistance but the feathered men attack and kill him while the woman looks on calmly.
Carl arrives at the art exhibit reception and talks with Professor Rodriguez. Rodriguez talks about Nanautzin, the warrior head of the cult of the evil god Tezcatlipoca. After he was defeated by the Spaniards, Nanautzin had himself mummified until the millennium. The Aztec empire fell in 1507, and the Aztec millennium is 520 years, 10 times 52. So the Aztec rebirth is to begin in 2027, 52 years in the future. In the new millennia Nanautzin is to rise and lead the new era on behalf of his dark god, and that he will rise every 52 years along the way and obtain sustenance from heart sacrifices. Rodriguez says how dark deeds are not permitted within sight of Venus, and that there must be five deaths, but only four victims. The first four must be brave warriors without blemish, while the fifth must be attractive and receives whatever he or she wants for a year. The "perfect victim" was taught to play the flute, and given three women named after the goddesses of the wind – Vixtociotl, Xilonina, and Altaonan. Or as Carl figures out, Vicky, Nina, and Lona. It's clear that Pepe is the "perfect sacrifice."
Carl sneaks into Tony's office and Tony interrupts him. Andrews and Pepe are both gone and Carl is going through Tony's personal phone directory. He's determined that Nanautzin will claim the last heart and then go back into dormancy when Venus comes out from behind the moon at 12:10 that night. Carl is looking for the highest flight of stairs in Chicago and needs to contact Tony's friend in the building department. Tony refuses and Carl heads for the sports arena.
Carl finds the place seemingly abandoned with only 23 minutes until Venus rises at 12:10 a.m. But he hears flute music and investigates to find two of the feathered men bringing out a wheeled stretcher-trolley. Carl goes back the way they came and finds Pepe in ceremonial garb, with his consorts playing the flute and preparing him for the sacrifice. He gives each of them a gift and then they depart. Carl confronts Pepe who admits he gave their word and so has Andrews and his cult. He is happy with the deal rather then his life as a box boy, and his mother will have all of her needs provided for. Carl suggests they might not live up to the contract, but then the cult members arrive. Pepe orders them to keep Carl alive…but they'll only obey him while he's alive.
Pepe drinks the drug to kill the pain then he goes out to the arena with Carl led by the cultists. The high priest is waiting for Pepe along with the sarcophagus holding Nanautzin. Pepe lies upon the sacrificial altar with only six minutes left. At the last minute Pepe reconsiders the deal, leaps off the altar, and runs off. The guards go after him, shoving Carl down the stairs where he sprains his ankle. Nanautzin rises from his bier, grabs a sword, and comes down the stairs after Carl. Carl just notices the approaching mummy and tumbles down a few more stairs. He turns to see that Nanautzin has vanished. However, it's only 12:08. Carl hobbles down a few more stairs…and Nanautzin appears behind him. He misses with one final swing and collapses on top of Carl – Carl's watch is slow.
Carl is at Rodriguez' exhibit considering the Nanautzin mummy and talking about how Pepe is working as a box boy downstate. Carl is left to wonder if Nanautzin will rise in 52 years since he didn't get his fifth sacrifice.