While the police suspect a drug dealer on trial is behind the murders of the State's witness in his case, as well as his girlfriend, Patrick Jane sees a different motive for the crime - as well as a different suspect.
An FBI agent takes over the case when a two-year-old girl is kidnapped and a hefty ransom demand made. Despite instructions from Beckett to stay away from the investigation, Castle gets involved when he finds out that the FBI agent is her ex-boyfriend.
After communications with the president's plane are lost, Elizabeth is sworn in as the acting president. Henry is asked to recruit one of his students for the NSA.
When a government employee is kidnapped in Afghanistan, Elizabeth takes advice from former Secretary of State Madeleine Albright, clashing with the president's recommendation.
When dealing with the Russian government, the president's administration comes across hostility. Dmitri is interrogated about being a spy.