An investigator is trying to determine whether a foreign intelligence service knew a journalist was arriving in a particular city before his plane landed. She has access to: (1) 1970s commercial airline passenger manifests, which were routinely shared with destination country immigration and security services; (2) a documented CIA station in the destination city with an active operational relationship with the host country's state security service; (3) evidence that the journalist's intelligence file existed at CIA headquarters. The journalist was met at the airport by an unknown party and killed three to five hours later. Construct the most parsimonious information chain that explains how local security services knew who was on the inbound flight before it landed.