Murphy) and Charlie Cole (David Reale). Several supporting characters from Conviction reappear, including Victor Coste (Howard Siegel), Patricia Caldwell (Mimi Kuzyk), and Andriy Kobin (Elias Toufexis), as well as interactive telephone conversations with Sarah Fisher (Victoria Sanchez). Plot Two years after Third Echelon is dissolved, Sam Fisher takes up work as a contractor for Paladin 9 Security – a private military company run by his friend Victor Coste. While assigned to a USAF base in Guam, terrorists assault the installation, executing its commander and killing hundreds of service members, while heavily injuring Coste. A faction known as the "Engineers" publicly takes responsibility for the attack, announcing it will launch a series of weekly "Blacklist" attacks on the United States until it recalls its troops deployed abroad. U.S. President Caldwell assigns Sam and his colleagues – tech expert Charlie Cole, CIA operative Isaac Briggs, and technical analyst Anna Grímsdóttir – in to the newly formed Fourth Echelon, a new top secret special-ops and counter-terrorism unit which operates out of a converted military cargo plane known as "the Paladin". Fourth Echelon traces the weapons used in the Guam attack to arms dealer Andriy Kobin, a former target of Sam's operating in Benghazi. Through him, the group trace his buyers to Iraq, whereupon Sam learns that the Engineers' leader is Majid Sadiq (Carlo Rota), a former MI6 agent. Learning a Blacklist attack is targeting Chicago, Sam infiltrates the site of the attack and prevents the release of a biological toxin into the city's water supply. Fourth Echelon traces the supplier to Iran-affiliated mercenary broker Reza Nouri (Sam Kalilieh), whom Sam extracts from Paraguay before a team of Iranian Qods Force commandos can kill him. Nouri willingly supplies information that leads Fourth Echelon to finding evidence linking the Engineers as an Iranian outfit. However, while seeking further evidence to support this, from within the Qods Force headquarters in Tehran, Sam finds the Engineers falsely implicated Iran in the attacks, in order to raise tensions between the Iranians and the United States. After successfully stopping another attack in Philadelphia, forcing the Engineers to increase their attacks to one per day, Sam and Briggs travel to the Guantanamo Bay detention camps when Fourth Echelon learns that Nouri is feeding false information to the CIA to reignite tensions between the U.S. and Iran. Their interrogation of Nouri reveals that Sadiq sought to distract the US government from