Jack Ryan (Ford), a retired CIA analyst is on vacation with his family in London. After giving a lecture at the Old Royal Naval College in Greenwich, Ryan and his family witness a terrorist attack on Lord William Holmes (Fox), British Secretary of State for Northern Ireland. Ryan intervenes and disarms one of the assailants, and kills another two with the disarmed assailants firearm. Injured by a shot to the shoulder, Ryan waits for the police to respond, as the remaining terrorists flee. Whilst recovering, Ryan testifies in court against Sean Miller (Bean), a member of a Provisional Irish Republican Army splinter group. Sean is the assailant Ryan was able to neutralise in the attack against Lord Holmes, but had also killed his younger brother, Patrick Miller in the ensuing gun battle. Sean is later convicted for his crimes.En route to Albany Prison on the Isle of Wight, Sean's prison convoy, escorted by the Police is ambushed by his comrades, including Kevin O'Donnell (Bergin). The Police Officers are executed, including Inspector Robert Highland (Threlfall). Free once more, Sean and his comrades flee to Northern Africa to plan their next kidnapping attempt on Lord Holmes. Seeking vengeance for his brother, Sean tries to convince several members of the splinter group to go to America with him, to kill Jack Ryan and his family. Ryan is later informed of Miller's escape by Vice Admiral James Greer (Jones), and Marty Cantor (Freeman), a former colleague of Ryan's, who mentions that it is possible Sean has fled the country, thereby indirectly implying Ryan's life is in danger. Greer attempts to recruit Ryan back into the C.I.A.. Ryan however refuses, confident that the IRA will not follow him to America.London, where the opening scene takes place. (Westminster Bridge over the Thames)Meanwhile, in England, Lord Holmes is informed of Sean's escape by both his assistant Watkins (Fraser) and Sergeant Owens (Armstrong). Considering the complexity of Sean's transfer (Inspector Highland being the only person with knowledge of the route to Albany Prison, including decoy routes and phoney convoys), Watkins and Owens conclude that there must have been an informant. Owens suggests that Lord Holmes lay low for a while, and postpone his appointments as Secretary to Northern Ireland. Holmes refuses to allow the IRA dictation over his position and authority.At the U.S. Naval Academy, Ryan discusses the attack in London with Lieutenant Commander Robby Jackson (Jackson). As this occurs, Ryan's wife picks up their daughter from school, not aware that Sean is pursuing behind them. Simultaneously, Ryan is followed by two affiliates of Sean including Annette (Walker), one of the members who saw to Sean's earlier escape. Ryan narrowly avoids the attempt on his life, however his wife and daughter are seriously injured after being run off a busy highway by Sean, and crashed into a median. Ryan's daughter, having sustained life-threatening injuries has to have her spleen removed. A CNN broadcast highlights that the IRA, through Sinn FÃ©in representative Paddy O'Neill (Harris), did not support and also condemn Sean's attack. O'Neill offers his apologies for the attack, however Ryan refuses to accept, instead returning to the CIA to ensure his family's safety from further attacks.In Belfast, Ireland, an anonymous tip-off prompts Sergeant Owens to conduct a raid on a safe-house that is possibly holding Sean. But whilst arrests are made, Sean is not identified. Ryan deduces that the tip off was deliberate, noting that several IRA commanders were recently killed, hypothesising that a splinter group must be coordinating the attacks. He notes that police surveillance photos of a woman with long red hair (Annette) must have something to do with it, and that if she is found, Sean will also be found as well. Meanwhile, Sean, Annette and O'Donnell, as well as several of his comrades have taken refuge in a training camp in Libya. Sean is furious when he is informed that Ryan survived the assassination attempt. Back at home in Maryland, Ryan and his family return home, their house being outfitted with constant surveillance. Late one evening, Ryan receives a disturbing phone call directly from Sean, who proceeds to torture Ryan about his inability to protect his family, and revealing that he knows the consequences that befell his daughter.Fearful, Ryan meets with O'Neill, demanding information that leads him to Sean and O'Donnell. O'Neill refuses to sell out his fellow Irishmen. Ryan, unable to convince O'Neill, threatens to poison O'Neill's fundraising campaign in America by allowing the press access to his family - thereby highlighting the IRA atrocities committed against the Ryans, and would undoubtedly reduce Sinn FÃ©in influence. Later on, SO13 release information to Ryan that the weapons used by Sean and his comrades in London have been traced back to an Arms Dealer in Libya, but the exact whereabouts of it is unknown. To Ryan's surprise, O'Neill whistle-blows on one of Sean's associates, as she isn't Irish (O'Neill had previously told Ryan that he would not sell out his countrymen, but given that Annette is English, this invalidates O'Neill's morals.) Sergeant Owens meanwhile, is performing surveillance of a suspected affiliate of Sean, posing as a rare book collector. After smoke emits from one of his lights, an electrician discovers Owens' camera, blowing Owens' investigation and also alarming the Owner. Owens gives pursuit, but the owner manages to evade arrest, and flees to North Africa to join Sean. However, The Librarian who is briefly identified as Dennis is of no further use to Sean or O'Donnell, and is subsequently executed.The go ahead is given for the British Special Air Service to conduct a raid on a specific camp, spotted through American satellites that Ryan believes identify the English redhead. The SAS kill everyone in the camp, but unknown to Ryan, Sean and his close associates had previously fled the camp to Washington, as Lord Holmes has gone there to present Ryan with his KCVO medal, therefore presenting an opportunity to kill Holmes, and for Sean to enact his revenge.A storm supposedly knocks out power to the Ryan residence, but since nearby street lights and adjacent buildings remain lit despite the 'outage' he realises that someone must have knocked out the power deliberately, to their property only. Sean's team kill the U.S. Diplomatic Security Service agents as well as Maryland State Police troopers, rendering the Ryan residence totally defenseless. As Ryan and Jackson move to secure the house, Watkins emerges from the cellar where the power switch is, confirming to Ryan his own suspicions that Watkins is the informant. Shortly after, Sean's men assault the house and attempt to kidnap Lord Holmes, Ryan however leads him and his family to safety, and lures Sean and his comrades away from the home.Marty alerts the FBI's Hostage Rescue Team to the Ryan residence. Sean, O'Donnell and Annette follow Ryan to the shoreline, believing Holmes is with him. They pursue Ryan by boat, but O'Donnell realises that Ryan is alone, leading Sean away from Lord Holmes. Annette and O'Donnell try to persuade Sean to turn around, but an enraged Miller kills them both, adamant at claiming his revenge. Sean disables Ryan's boat by shooting the engine. Ryan gains the upper hand in the subsequent fight with Sean, and impales him on the anchor, killing him. The boat crashes into a reef and explodes, allowing the Rescue Team to find Ryan and bring him back ashore. The film ends with the Ryans resuming their normal life, which includes Mrs. Ryan expecting another child, and receiving the call from their obstetrician confirming the sex of the baby.
Output: Question: Who gave O'Neill information about the weapons used by Sean and his comrades?, Answer: SO13