The Nest (2020) Plot Summary & Ending Explained

Stressed by a crumbling marriage and battling alcohol issues, Dr. Ben Cahill finds himself paralyzed by pressure in the emergency room. Following a severe breakdown, his superior mandates a break, prompting him to retreat to Orr Island, a serene fishing community off the coast of Maine, where he and his ex-spouse once bought a home.

During his stay, at the behest of Sheriff Hobbs, he begins to investigate a series of bizarre cases involving both animal and human corpses that exhibit unusual internal and external injuries. As he delves deeper, Dr. Cahill makes a shocking discovery: one of the invasive red cockroaches infesting the island possesses pincers, a trait that signifies something far more sinister. Concerned, he reaches out to the local university's entomology department, only to learn that this particular African species remains largely unknown in their studies.

With the cockroaches also invading his abode, Dr. Cahill faces hostility from the tight-knit island community. An altercation escalates when a local named Jack breaks into his house, only to meet a gruesome fate at the hands of the very insects he's been studying. Afterward, the sheriff permits Dr. Cahill to conduct an autopsy on Jack's body, leading to a terrifying revelation: these cockroach-like creatures invade human hosts, consuming their internal organs before violently surfacing.

As tensions mount, rumors spread throughout the town, blaming Cahill for the recent deaths. Mobs form, resulting in him and his girlfriend, Nell, being imprisoned. In a dramatic turn, Sheriff Hobbs finds himself ensnared and ultimately murdered by the insects, his death being discovered by a local named Guy.

Once freed, Cahill and Nell race to evacuate the locals, starting with Nell's mother and her schoolchildren, although they soon discover one child is missing. The couple bravely rescues the boy, uncovering the horrors of a cockroach nest hidden in a barn. With urgency, they try to inform the increasingly skeptical townsfolk of the looming threat, but chaos ensues when a swarm of these mutant insects darkens the skies.

Realizing the gravity of the situation too late, many locals attempt to escape but face catastrophic losses, including Eamon and his gang. In a desperate bid for survival, Cahill, Nell, Guy, and Henry flee by boat towards the mainland. However, they encounter another relentless attack, forcing them to overturn their vessel. In a stroke of luck, they ignite a fuel pump, incinerating a significant portion of the infestation just as military reinforcements are called in.

Yet, the film closes on an ominous note, revealing that one of the deadly insects has successfully made its way to the mainland, leaving viewers with unsettling uncertainty about what’s to come.

At the end of The Nest, Rory's realization sinks in that his obsession with wealth and his ongoing lies cannot sustain his family or himself. After being abandoned at the restaurant by Allison, Rory makes his way home, where he finds his family having breakfast—an image that hints at the possibility of reconciliation or at least a moment of clarity. Despite his hopes to fix everything with a new venture and start fresh, the film leaves his future uncertain, ending with Rory broken and crying at the breakfast table. His intense breakdown and the conversation with the cabbie earlier suggest he's finally understood that his relentless pursuit of money has only brought instability and pain. His past delusions of wealth—once believing he'd had a million dollars—highlight the emptiness of his ambitions, showing that success was never truly rooted in financial gains but in love and stability. The film ends on this ambiguous note, implying that Rory has learned the gravity of his mistakes, but whether he can truly change remains unanswered.

Allison's horse, Richmond, serves as a powerful symbol. Initially a beloved pet, Richmond’s failing health and tragic death mark the end of her patience and hope for her marriage—her grief punctuated by her frantic care for the horse's body. The horse’s death echoes the breakdown of her relationship with Rory, symbolizing that her marriage is as fundamentally exhausted as Richmond was. The haunting atmosphere of the family estate further reinforces this, with strange noises and the house’s empty, almost ghostly interior reflecting Rory’s false promises and the superficiality of his wealth. The house itself embodies the corrupting nature of materialism—beautiful on the surface but hollow inside—mirroring Rory’s character and the life he tries to project.