In a gripping tale, Indian Army Chief COAS General Pratap Malik (Vikram Gokhale) initiates the formation of a covert intelligence unit known as DSD (Data Systems Diagnostics), which operates directly under the Army Chief's command and is authorized for secretive missions behind enemy lines. He appoints Colonel Abhay Singh (Manoj Bajpayee) to lead this elite unit, which quickly assembles a skilled team, including Major Jai Bakshi (Sidharth Malhotra), Lt. Col. Anees, and Captain Maya Semwal (Pooja Chopra). Over the years, they embark on numerous successful covert operations across the globe.
During a routine telephone surveillance in New Delhi, Jai intercepts a conversation involving Lt. Gen. Gurinder Singh (Kumud Mishra), a former Army officer connected to the Indian Arms lobby, who tries to bribe the Army Chief with a hefty offer of $2.5 million. The Army Chief's resolute refusal enrages Gurinder, who boasts about his knowledge of DSD and later threatens to expose the unit, raising alarms within the Army. In a bid to mitigate the risk, the Army Chief informs the Defence Minister about the foreign military-industrial interests trying to manipulate the Indian arms market, but his plea for intervention is met with resistance.
Growing suspicious of a widespread scam, Jai engages in unauthorized surveillance to unravel the truth. After two months, he makes a drastic decision and, accompanied by his girlfriend Sonia Gupta (Rakul Preet Singh), escapes to London with sensitive data that he pilfered from the DSD headquarters. Captain Maya alerts Abhay about Jai's actions, prompting him to activate his intelligence network and launch a manhunt.
Meanwhile, Brig. K Srinivas backs Gurinder and spies on Abhay, but Abhay cleverly evades capture while DSD relocates to a secure location. Frustrated by their setbacks, Gurinder collaborates with a journalist to commence a smear campaign against the Army Chief. Crisis escalates as General Malik reveals to Abhay the impending shutdown of DSD, the foreign implications surrounding Indian defense deals, and Gurinder Singh’s illicit connections to Mukesh Kapoor (Adil Hussain)—a London-based arms dealer deeply entangled in this scandal.
Abhay, undeterred, vows to safeguard the reputation of the Indian Army and bring those responsible for the corruption to justice. He assembles his team and reaffirms their commitment despite governmental disavowal. Confronted by Jai, Abhay accuses him of cowardice, while Jai defends his betrayal as a stand against systemic corruption. In London, Abhay connects with an intelligence intermediary, Tariq Bhai (Anupam Kher), in hopes of locating Jai.
As tensions escalate, Abhay entraps Mukesh Kapoor by revealing that Jai possesses damaging data about his business dealings, compelling Mukesh to orchestrate Jai's elimination—a plot foiled by Abhay’s warning to Sonia. A violent confrontation ensues, leading to significant casualties and injuries.
Angered and outwitted, Mukesh captures Tariq but suspends his execution when Jai offers to surrender sensitive information for a personal meeting. Jai then divulges a major housing scam involving Gurinder Singh and the Defense Minister, with key evidence hidden by Baburao Shastri (Naseeruddin Shah), an eyewitness to the corruption. This revelation triggers rapid action: Abhay rushes back to India, obtains Baburao's confession, and engages with the journalist previously involved with Gurinder to ensure the truth is revealed.
As the plot thickens, Brig. Srinivas captures members of DSD and rescues Gurinder, yet the authority absolves DSD of wrongdoing as the housing scam breaks wide open, leading Gurinder to take his own life in a moment of despair.
In a poignant final encounter, Jai bids farewell to Abhay, who continues his service as the steadfast defender of his country, embodying the tenacity and resolve against corruption.
