Ross set up a meeting with Neil Daniels, a source within the CIA who was involved in Operation Treadstone. He traveled to Turin to meet Daniels and learned that Bourne was just the tip of the iceberg. Daniels informed him about Operation Blackbriar, the Treadstone upgrade, involving more clandestine assassins.
Meanwhile, Bourne saw an article in The Guardian by Simon Ross, detailing the various events of Bourne's past and describing him as a CIA officer. Ross, who was returning to London, told his colleagues back at the office that he had learned about Operation Blackbriar. The CIA substation in London used ECHELON technology to pick up on the word "Blackbriar", causing section chief Noah Vosen to authorize surveillance for Ross.
Bourne then contacted Ross at his office and arranged to meet at Waterloo station. After receiving the phone call, Ross took a taxi to the station but was pursued by the CIA, who believed him to be meeting his source there. At the station, Bourne saw CIA officers following Ross and placed a prepaid mobile phone on him; through it, Bourne instructed the bemused journalist to dodge the station's surveillance, while Bourne knocked out the agents attempting to kidnap Ross.
However, Noah Vosen ordered an assassin named Paz to kill Ross and his source. Vosen's team identified Bourne on a security camera and recognized him as a Treadstone assassin, assuming he must be Ross's source. Bourne advised Ross to remain hidden, but Ross panicked and revealed himself, giving Paz a window to assassinate Ross. In the ensuing chaos, Bourne stole Ross's notes from his jacket, evaded being killed as well & leading Bourne to Ross's source.