Margo Green pushes Frock’s wheelchair into the chaotic gala. They head toward the Hall of the Heavens, where Wright, Cuthbert, and the mayor stand on a platform near the Superstition entrance. Frock tells Margo they must stop the event. They find Kawakita and plead with him to cancel the ceremony. Margo explains their discoveries about the creature, but Kawakita dismisses their claims and urges Frock to join the platform.

Frock rolls forward and shouts that a deadly beast is loose in the museum. The crowd murmurs and backs away. Cuthbert confronts Frock, accusing him of sabotage, then returns to the platform. Margo suggests they find Pendergast, the only person with enough authority to help.

After Wright’s speech, Cuthbert presents giant scissors to the mayor, who cuts the ribbon and opens the exhibition. D’Agosta enters first and confirms the space is clear. He is followed by Ippolito and the dignitaries. The crowd surges in. Inside the dimly lit exhibition, D’Agosta inspects side alcoves and notices a mummy case with blood streaks, soon discovering a dead body hidden atop the case.

He radios security command just as nearby guests notice the blood. Someone screams that it is a real body. Panic erupts. The crowd pins D’Agosta against the case, which topples. A bloody, headless corpse slides into the crowd, causing utter pandemonium. People stampede, and D’Agosta’s radio is knocked from his hand.

In the rotunda, Frock learns that Pendergast radioed from the basement an hour ago and insists that he and Margo go down themselves to find him. Margo hesitates but agrees. In the dim corridors of section 29, formerly part of the old power plant, Frock repeatedly calls for Pendergast but receives no reply.

In the computer room above, Officer Waters hears running feet and faint screaming overhead. Another thump comes from the electrical room. Unable to reach backup due to the stampede upstairs, he follows the computer technician into the dark electrical room. Suddenly, he panics at a noise, firing three rounds into the failing air-conditioning pump and destroying the central electrical switching box. Sparks fly, alarms sound, and the lights go out in the entire museum.

The narrative rolls back in time slightly to the start of the panic. Coffey receives frantic radio reports from the Hall of the Heavens and orders emergency crowd control. Suddenly, Ippolito’s colleague, Garcia, reports total security system failure. A heavy metal security door descends from the ceiling, sealing the hall’s east entrance. Garcia reports that the doors operate independently of the power grid and cannot be raised. Guests flee into the rain as the lights go out and the door continues its descent.

In the basement, Pendergast locates a hidden plastered-over doorway and kicks it open to reveal a service tunnel. He hears Frock faintly calling his name.

Pendergast detects a peculiar smell and hides in a storage room. Through a small window, he watches a large, dark, hairy creature snuffling at his door. After it moves on, he emerges and fires his weapon. The bullet ricochets off the creature’s skull, and the creature vanishes around a corner as the lights go out.

At the hors d’oeuvres table, Smithback is engulfed by the stampeding crowd. He rolls under the table and watches the chaos. Recognizing a major story, he pulls out his microcassette recorder and begins dictating as the lights go out.

In the basement, Margo and Frock search for Pendergast. The lights dim, a gunshot rings out down the hall, and then darkness falls completely. Margo notices the same foul, goatish smell from the exhibition. Frock urges her to save herself. Margo refuses and guides his wheelchair into a storage room, slamming and locking the door just as scraping begins on the other side.

In the deserted gallery, D’Agosta examines the headless corpse that started the panic; his fellow officer, Bailey, identifies the victim as Fred Beauregard, who has been missing since Wednesday. The lights go out. They navigate to the exhibition entrance, which is blocked by collapsed stelae that have crushed several people, including two officers.

D’Agosta finds guests trapped against the fully shut emergency door, with injured people pinned beneath it. Ippolito’s manual override code fails. D’Agosta organizes the survivors, calms the crowd and radios Coffey about the casualties.

Pendergast radios D’Agosta to warn that a large, non-human creature is loose, can open doors, and is immune to direct gunfire. He stresses that his .45 bullet ricocheted off its skull and warns D’Agosta that the creature is likely approaching his group right now.

As D’Agosta, Bailey, and Ippolito cautiously approach the nearby stairwell, the creature ambushes them from above, killing Ippolito instantly. D’Agosta fires wildly, then spots a large shape crouched over an injured man in the hall. He fires again, and the creature flees into the exhibition. D’Agosta finds the man’s skull split open, slams the exhibition doors shut to trap the creature inside, and orders everyone down the stairwell. Wright, Cuthbert, and Rickman refuse to accompany him, retreating instead to the fourth floor. D’Agosta leads the remaining group, including the mayor, downward.

Coffey dismisses Pendergast’s warning and moves to the mobile command unit. Garcia reports total system failure; backup power has not engaged, and all five security cells are sealed. Security Expert Tom Allen explains that Officer Waters shot the main electrical switching box, causing a chain reaction. The best way to access that part of the museum now, he advises, is to enter through the roof of cell four and go down through a chandelier access port in the hall ceiling.

D’Agosta radios to report that the creature killed Ippolito and they are retreating to the subbasement. An infuriated Coffey relieves him of duty and tries to appoint Sergeant Bailey as the leader, but Bailey confirms D’Agosta’s account, states that D’Agosta remains in charge, and cuts the transmission.

Outside in the rain, Kawakita stands motionless amid the chaos, replaying Margo and Frock’s warning in his mind, then turns and walks thoughtfully away into the darkness.

Pendergast knocks on the storage room door, and Margo lets him in. He confirms the shots were his and explains it is too late to evacuate—the museum has been sealed into five isolated cells. He describes the creature as a powerful quadruped identical to the Mbwun figurine; he had fired two shots at it before it came to their door. A jammed stairwell door now prevents them from escaping upward, but the blueprints show a route through the subbasement.

Margo and Frock agree to share everything they know about the creature. Pendergast identifies a distant drumming sound as D’Agosta’s group running down the stairwell.

Wright, Cuthbert, and Rickman take refuge in Wright’s fourth-floor laboratory. Wright retrieves a Ruger magnum and a bottle of Scotch; he plans to wait for the creature to pursue D’Agosta’s group, then escape through a forgotten passageway inside the exhibition. As Wright drinks heavily, old grievances surface. Cuthbert blames Wright for covering up a researcher’s disappearance and refusing to report an unexplained bloodstain near the Whittlesey crates. Their conversation reveals that Cuthbert hid Whittlesey’s journal. Cuthbert accuses Wright of ignoring years of reports about strange sightings of the beast.

In the stairwell, D’Agosta’s group finds the basement door jammed shut by earlier shotgun blasts. Detecting the creature’s smell from above and spotting two red eyes in the dark, Bailey fires, and the group flees to the subbasement. D’Agosta forces open a heavy metal door and leads the 38 survivors into the flooded lower level.

In the basement storage room, Margo and Frock outline their theory, and Margo proposes using the beast’s keen sense of smell and reliance on the plant material to lure it into a trap. Pendergast radios D’Agosta, giving him directions through the tunnels, and he agrees to stay behind with Margo and Frock to draw the creature away. He then radios Coffey with a warning to heavily arm the rescue team. Coffey dismisses the warning, and Pendergast signs off.