The story unfolds with the Anti Terrorist Department executing a critical mission when a terrorist seizes a bus full of hostages. Enter Raghuram "Raghu" Rathod, portrayed by Emraan Hashmi, who, alongside the courageous officer Siya Verma (Amyra Dastur), successfully navigates this precarious operation. However, the mission nearly costs Raghu his life. In a moment of vulnerability, Siya confides in Raghu that she struggles with the chaos of life and the possibilities of separation, prompting him to propose. They eagerly anticipate their marriage.
On the eve of their wedding, their plans take a drastic turn when ACP Bhardwaaj (Arunoday Singh) summons them. A sinister plot aimed at the state’s chief minister surfaces, thrusting them back into danger. Bhardwaaj concocts a gruesome scheme forcing Raghu to kill the CM under threat; if he refuses, Siya, on duty elsewhere, will be killed by a sniper. In a tense confrontation with the CM's son Aditya, Raghu makes the harrowing choice to comply with this demand, resulting in murder and unforeseen consequences.
Aditya, who orchestrated his father’s demise to ascend to power, finds himself trapped by Bhardwaaj and his associate Tiwari. Soon, these events spiral into a violent confrontation in an abandoned factory, where Raghu is left for dead but miraculously survives, though severely burned. He seeks help from his friend Popo (Tanmay Bhat), who introduces him to a laboratory where his sister explains a dire prognosis involving radiation. Raghu's life changes dramatically after consuming an experimental potion that triggers complete cell regeneration, rendering him invisible to all light except neon and direct sunlight.
This change, however, takes a toll on Siya as she believes Raghu has betrayed her by taking a life. Distraught, she immerses herself in work to escape the heartbreak. Meanwhile, Raghu, filled with vengeance, sets out to exact revenge on those who wronged him, starting with Tiwari. After a drunken drive home, Raghu confronts Tiwari, issuing a chilling ultimatum — he'll die within 24 hours. Tiwari dismisses his warning, but chaos ensues when Raghu does indeed kill him. In her effort to protect Tiwari, Siya uncovers Raghu's presence but is unable to detain him. Despite her growing compassion, she is unaware of Bhardwaaj's true involvement in the CM's murder.
As tensions escalate, Siya informs Bhardwaaj that Raghu has transformed into the shadowy figure known as Mr. X, intent on killing Aditya. Bhardwaaj then assigns Siya to protect Aditya. In a gripping confrontation, Raghu successfully dispatches his second target, Aditya. However, their entwined fates complicate as Siya is torn between her duties and her feelings for Raghu. During tranquil moments together, love blossoms, until they are abruptly caught in a police raid, leading to Raghu's arrest.
Subsequent events unfold with Raghu facing Bhardwaaj, who seeks to eliminate him for good. After Popo's desperate message reveals Bhardwaaj's intent to kill Raghu, Siya rushes to intervene. A fierce battle ensues, where Siya implores Raghu to spare Bhardwaaj. She turns the tables on Bhardwaaj by recording his incriminating confession, shared publicly during a press event. When Bhardwaaj attempts to harm Siya, Raghu steps in, ultimately leading to a climactic rescue. The movie arcs through themes of love, betrayal, and redemption, posing questions about the moral complexities of justice and vengeance in a tumultuous world.
