The fourth episode of Dept Q unfolds with haunting glimpses into the past. Merritt, with William's hat in hand, retrieves it from the ferry only to be abruptly seized and whisked away into the rear of a vehicle by a voice that strikes an eerie chord of familiarity. Upon awakening, she discovers herself confined within a pressurized tank, the claustrophobic surroundings amplifying her unease.
In the contemporary timeline, Carl makes his way to his therapy session with Rachel. As their discussion veers towards Jasper, Rachel perceives the weight of bearing responsibility down on Carl, exacerbating his internal struggles. Unfortunately, just as they delve deeper, time runs out, and their playful banter spills out the door, lightening the tense atmosphere momentarily.
Returning to the precinct, Carl overhears Logan probing into the shooting case and feels compelled to intervene. The initial hypotheses—that the shooter gained entry through the rear or arrived ahead of time to lay in wait—begin to crumble under scrutiny. Carl points out the mountain of bins blocking the back door, rendering a stealthy entrance nearly impossible.
Furthermore, CCTV footage captures an individual at McDonald's a quarter-hour before the shooting commenced, posing a significant timing challenge for a single gunman to break in and conceal himself. So, what is the revelation here? Carl posits a groundbreaking theory: there could have been more than one assailant, an angle previously overlooked, perhaps both lying in wait within the car until their targets appeared.
Elsewhere, Rose finds herself in conversation with Hardy, her spirits dampened by her exclusion from the case. She dismisses the Mhor situation as inconsequential, oblivious to its gravity until Hardy corrects her perspective. He advises her to seek out the constable, urging her to win him over by making him feel valued and integral to the process.
Hardy urges her to delve deeply into the everyday routines of Merritt's life and, particularly, to uncover any disruptions or ripples that may have arisen following her mysterious disappearance. Rose subsequently arrives at Mhor, where she first sweet-talks Cunningham before shifting her focus onto Jennings. It is here that she discovers a revealing piece of information: Merritt had returned for Jennings' funeral, suggesting a profound bond between the two. Furthermore, there are hints that Merritt might have been involved in a robbery, given that Jennings' family was in dire straits and their business was on the brink of collapse. Such a crime could have been the very thing they needed to revive their fortunes.
Rose, accompanied by Colin—the Constable's son, whose relationship with Cunningham is anything but amicable—heads to the Jennings residence. During their visit, Colin reveals a technical photograph of the room where William was found. Someone, presumably Cunningham, had circled an item on the floor with a black marker—a necklace, to be precise. Meanwhile, Clive Jennings' business deals in hazardous materials, though the exact nature remains unclear. The presence of numerous dead birds in the vicinity offers a potential clue, but Rose departs empty-handed for now.
Returning home, Carl finds himself visited by his estranged ex, Victoria. She sits with Martin in the kitchen, sipping wine and eventually broaching the subject of Jasper, who looks up to Carl despite his absence. Carl dismisses the idea that Jasper truly cares until Victoria mentions that Jasper stayed with him throughout his hospital stay. Her probing questions about the kind of example he's setting give him pause for reflection.
Martin holds a conviction that Victoria has uncovered something significant and eagerly seeks to delve into discussions about Leith Park that very night. Carl, despite his lack of enthusiasm, reluctantly opens up, unburdening himself with the guilt that weighs heavily on his heart. He recounts how the bullet, destined for Hardy's spine, miraculously slowed as it pierced his neck, ultimately sparing his life. This heartfelt confession promptly silences Martin.
Meanwhile, in the basement, Akram and Rose engage in an intense discussion, unraveling new insights from the crime scene photographs. The necklace circled in one of the images matches the chain Merritt had taken from Jamie, which originally belonged to Lila. Intriguingly, it was listed in the insurance claim but was retrieved by Lila on the day of Jennings' funeral.
Upon learning of Rose's findings, Carl challenges her theory regarding the bird and its mysterious connection to the boat. Rose concedes her uncertainty, acknowledging that the puzzle pieces don't fit seamlessly together. Merritt appeared to be a recluse, devoid of friends, and there's little evidence to suggest her life underwent any significant transformation following her disappearance.
The sole exception lies in a letter Merritt received from an individual named 'S,' possibly an old lover. Intrigued, Carl discovers a woman named Sabrine who once worked in Merritt's office and brings her in for questioning. Sabrine is candid, dismissing the notion of a romantic relationship with Merritt due to her sexual orientation. She expresses admiration for Merritt, noting her disregard for others' opinions and her thriving on the hostility within her workplace.
Among Merritt's colleagues, Stephen Burns emerges as a potential figure of interest, prompting Carl to hastily confront him at a pub. The conversation is tense and contentious, leaving the question of whether Stephen is indeed the enigmatic 'S' unresolved. The episode concludes with this mystery still lingering in the air.
Earlier, Sabrine had directed attention towards Merritt's colleague, Liam Taylor, a figure who was also familiar to Carl. With curiosity piqued, Carl approached Liam and uncovered a salacious tale. Liam had indulged in a month-long affair with Merritt, a secret he diligently kept from his wife. The liaison, seemingly devoid of emotional depth, concluded abruptly by Merritt, met with a casual dismissal from her: "Thanks, see you around," she remarked nonchalantly.
Their trysts transpired at the Prince's Garden Hotel, where Merritt, under the alias Lila Graham, always footed the bill. This alias was so ingrained that she even possessed a card bearing this name. The affair predated Merritt's disappearance by a year, adding another layer of complexity to Carl's investigation.
Determined to uncover the truth, Carl rushed to the hotel, pressuring the receptionist for answers. Under his relentless questioning, the receptionist finally buckled, revealing that Lila Graham—or whoever was using that name—had occupied the same room six times within two months prior to Merritt's disappearance.
Yet, despite Lila Graham's name being registered in the hotel's system, it didn't conclusively prove Merritt's presence. Liam Taylor's signature authorized the bookings, yet it was another man, Sam Haig, who was actually there during the final visits. This revelation raised more questions: What became of Sam? It emerged that Merritt had exploited him for sexual gratification, and his demise appeared intricately linked to her. But how, exactly, was the connection forged?
