As the Maze Virus continued to cast its dark shadow over Europe, the impact was particularly devastating in Ireland, where the crisis reached its peak. While a cure was eventually developed and successfully administered to 75% of the infected, the remaining 25% remained stubbornly resistant, leading to a tense division between the vaccinated, known as the Cured, and those who could not be healed, referred to as the Resistant.
Among those caught in this turmoil are Senan (played by Sam Keeley) and Conor (played by Tom Vaughan-Lawlor), both survivors who have been confined together in a rehabilitation center. With the vigilant supervision of Sergeant Cantor (played by Stuart Graham), they face the challenges of reintegrating into a society fraught with fear and hostility. During this tumultuous time, Senan unexpectedly encounters his sister-in-law Abbie (played by Elliot Page) and her young son Cillian, stirring painful memories of her missing husband Luke. Despite his outward pretense of ignorance regarding Luke's fate, dark flashes of his past haunt Senan, reminding him of the horrific acts he committed while under the virus's malevolent influence.
Conor, once a promising lawyer with dreams of a political career, now faces ostracism from his own family because of his horrific actions during the outbreak. In response, he establishes the Cured Alliance, an underground movement created to fight for the civil rights and recognition of the Cured—a marginalized group still grappling with the stigma of their condition.
As the government contemplates the euthanasia of 5,000 Resistant patients, tensions rise in a community already on the brink of disaster. Fears that the Resistant harbor a desire for another outbreak only serve to exacerbate the strife, igniting heated discussions throughout society. While working in a hospital facility that tends to the Resistant, Senan begins to uncover that their seeming indifference towards the Cured runs deeper than ignorance; there are unsettling truths that could unravel the social fabric.
Initially hesitant to join Conor’s group, Senan finds it increasingly difficult to ignore the reality of their situation, especially after witnessing the overt discrimination against the Cured. As he becomes embroiled in a planned act of arson under Conor's direction, they remain blissfully unaware that their every move is being monitored by Cantor, who grows ever more suspicious about their ulterior motives.
The situation escalates when Cantor delivers a bombshell to Abbie—the vaccine for the Cured may not have eradicated their primal urges but merely suppressed them. He presents a haunting photograph, suggesting Conor orchestrated Senan's violent actions while he was still infected, revealing a horrifying admission of guilt. This revelation throws Conor's past misdeeds into the light, including an admission of killing Abbie's husband during his infected state.
As the atmosphere becomes increasingly charged, Abbie confronts Senan, ultimately forcing him out of her home due to the darkness surrounding Conor's character. Realizing the true nature of the monster he once associated with, Senan makes a brave choice to align with Cantor in an attempt to dismantle the rogue Cured Alliance. However, their efforts go awry when Conor resorts to violence, brutally murdering Cantor as he escapes into the night.
Consequently, the Cured Alliance shifts gears, launching an assault on the Resistant, plunging the city into chaos and creating new victims in the process. In a show of force, the Irish Army is called in to restore order amidst the fervor. As pandemonium reigns, Senan seeks out Abbie, who is frantically trying to rescue Cillian from school, only to discover he has been bitten and infected by a rogue Resistant.
Risking it all, Senan manages to save Cillian but is then ambushed by Conor, who savagely attacks him. Just as Conor seems to gain the upper hand, a soldier intervenes, striking Conor down, but he escapes yet again. As normalcy begins to return, Senan reunites with Abbie and Cillian, only to face another heart-wrenching blow when their son succumbs to his new infection.
Months later, a news report reveals that “calm has been restored,” although the loss is immense with 8,000 new infected individuals now under government control. Promotional materials celebrating Conor's role as the voice of the Cured Alliance flood the media, while officials weigh the grim reality of euthanizing 25% of the remaining Resistant.
In the haunting aftermath, Senan goes into hiding with his newly infected son, leaving behind a profoundly altered world, forever scarred by the unspeakable atrocities that unfolded.
