Lucy awakens in her chamber, her gaze immediately drawn to a glass of water poised beside her bedside, a relic from the dawn of Lockwood & Co.'s fourth adventure. As she descends the stairs, the house echoes with an eerie silence, devoid of its usual inhabitants. A cryptic note awaits her, revealing that her companions have embarked on a perilous wraith hunt, leaving her to ponder their absence.
Noticing the basement door ajar, Lucy's curiosity is piqued, yet she hesitates, ultimately opting to secure the portal shut. Shortly thereafter, George and Lockwood storm through the door, their voices intertwined in a heated debate over a case gone awry—a single ghostly encounter unraveling into a swarm, their lives spared only by the timely intervention of Quill Kipps and his formidable team. Lockwood's ire burns brighter still at the thought of Kipps' dismissive stance towards their shared ordeal at Combe Carey Hall.
Amidst their concerns for Lucy, who they recount finding unconscious in the basement's depths and tenderly carrying to her sanctuary, she emerges unscathed, declaring herself in perfect health despite her 14-hour slumber.
The tranquility is shattered by a knock at the door, revealing Sebastian Saunders and Pamela Joplin, the enigmatic duo from Sweet Dreams Excavations, purveyors of the grave's darkest secrets. Lockwood attempts to decline their offer, yet Lucy's determination prevails, insisting that the agency's services are in demand. Bound by DEPRAC's stringent rules, the excavators seek their aid in unraveling the mystery of an unmarked grave that has summoned a formidable Type Two specter, with Sensitives on site reporting debilitating nausea.
As they journey towards Kensal Green Cemetery, Lockwood and Lucy engage in a captivating discourse on relic men—shadowy figures who pilfer ghostly Sources and peddle them on the illicit market. Their journey is further enlivened by the sight of fervent protests, cultists gathered near the cemetery's gates, their voices a chorus of dissent, advocating for the embrace of spirits rather than their relentless pursuit.
Upon arriving at the cemetery, a tapestry of characters unfolds before them—security guards, gravediggers, members of the night watch, and Sensitives, many of whom stand firm in their refusal to approach the grave until its safety is assured. Lockwood, ever the charmer, employs his silver tongue, assuring all that their well-being stands at the forefront of his team's mission.
Within the solemn chapel, Saunders recounts the tale of a tragic misstep, a casket left vulnerable at sunset's brink. The Sensitives' testimonies are a tangled web of sightings and sounds, each account differing vastly from the next. Saunders insists upon tackling the grave alone, but Lockwood's reminder of their agreed-upon support is met with a dismissive wave of the contract, Saunders disappearing into the shadows.
As they approached the unmarked grave, the trio relied heavily on their heightened senses. Lockwood scanned the area in vain for any telltale deathly glows, while Lucy's ears picked up a subtle, ominous vibration. They encircled the grave with iron chains, a ritualistic draw of straws determined George's fate—to be the one to unveil the coffin's secrets.
Suddenly, Lucy was overcome with nausea, and just as abruptly, Joplin appeared on the scene. George revealed that the coffin itself was forged from iron, a revelation that was met with the sound of buzzing flies now audible to Lucy, who shared George's queasy sensation. Lockwood urged them to press on, their mission paramount.
Lucy's mind wandered, lost in a flurry of flashbacks, until Lockwood's voice jolted her back to the present. Her haste in drawing her rapier left her with a painful cut, exacerbating the mental turmoil within. As Lockwood and George cleared the way to the coffin's lid, the decomposed form within—a skull with a gaping hole—was revealed under Lockwood's rapier's point. George, transfixed by the mirror clutched in the corpse's arms, was pulled from his reverie by Lockwood's forceful grasp. His cries shattered Lucy's reverie, and she swiftly cast an iron net over the macabre sight.
With the source contained, the other teams resumed their tasks. Lucy remained disconcerted, while George confessed that the mirror's abyss threatened to consume him. Lockwood assured them the ordeal was over, departing with Saunders to collect their due. Lucy's curiosity led her to a skull-shaped headstone, igniting a memory—the jarred skull had whispered to her, causing her fainting spell.
Meanwhile, Joplin probed for details about the corpse, prompting George to lead her closer for inspection. In a fateful misstep, he crossed the iron boundary, dislodging the net, and a smoky specter erupted from the remains. Lucy's rapier pierced the mist, George reinstated the net, and the ghost vanished.
Without hesitation, Lucy raced home, her heart pounding as she released the skull jar's latch. The jar seemed to relish their reunion, weaving tales of profound knowledge to lure her into revealing its secrets. It whispered of Lockwood's hidden agenda, a dangerous item locked away in his chamber. As Lucy neared, the jar sensed the power she had encountered, warning of impending doom.
George and Lockwood arrived, their tension palpable, their argument raging. Lockwood chastised George for his reckless actions, while George was consumed by the mirror's inscription and its implications for the Problem. Lucy burst in, brandishing the ghost jar and her tale of their enigmatic conversation. Both men dismissed her claims, but when she mentioned the room, Lockwood's anger flared. He warned her that another mention of the room would seal her fate at Lockwood & Co.
Distraught, Lucy immerses herself in a recording of Marissa recounting her encounter with a Type Three, detailing their stubborn refusal to relinquish their hold on the mortal world. A genuinely remorseful Lockwood approaches her chamber, offering to tend to the gash on her hand. She accepts his offer, and as he works, he apologizes for his earlier conduct, confessing that the door serves as a barrier to a painful past that's difficult to discuss. He further acknowledges the struggle of shifting the spotlight from himself onto others. Lucy senses his belief in her, and he vows to unravel the mystery together.
Embarking on a search for George, they discover he has deciphered the mirror's inscription and vanished from their midst. George returns to the chapel within the graveyard's embrace, only to find it adorned with crime scene tape, signifying a disturbance. Inspector Barnes soon appears, informing him that the mirror, once resting with the deceased, has been stolen. The case falls under the purview of Quill Kipps and his dedicated team, and by then, Lockwood and Lucy have also arrived on the scene, adding depth to the unfolding investigation.
Bobby, Kipps's diligent researcher, imparts to Barnes a fascinating revelation: the iron casket in question had a past in breweries. Amidst the tumultuous labor strife of that era, he speculates that it likely enshrines the hastily dispatched remains of a brewery's proprietor, whose demise was swift and burial hasty.
George, with a tinge of intrigue, points to the enigmatic inscription etched on the mirror's surface, translating to "The truth lies beyond." He contends that this is irrefutable evidence of the casket's sinister purpose—to ensnare something ominous and spectral, even predating the onset of the current Problem. He insists the occupant is none other than Edmund Bickerstaff, the graveyard proprietors' wayward son, notorious for his grave-robbing exploits. When Bobby seeks corroboration, George hands him Bickerstaff's staff, challenging him to uncover its hidden inscription. To Bobby's satisfaction, the Bickerstaff crest is unmistakably etched upon it.
Barnes, recognizing the gravity of the situation, assigns both teams the urgent task of recovering the mirror without delay. Outside, the air crackles with tension as Kipps taunts Lockwood, claiming this case is far beyond his grasp. Their words escalate into a heated exchange, culminating in a daring wager: a race to uncover the mirror, with the loser forced to abandon their profession forever. They seal the deal with a resolute handshake, setting the stage for a thrilling confrontation of wits and determination.
