Despite a successful first assignment, Annie's still the new girl in the DPD. That means drawing the worst assignments, like debriefing "walk-ins" - people who show up at the CIA Headquarters claiming to have intel, although they usually turn out to be crazy. During walk-in duty, Annie meets Helen Newman and her teenage son, Walter, who has intercepted and decoded information from a short-wave radio transmission. With Auggie's help, the DPD is able to confirm that the intelligence Walter intercepted was legitimate chatter from an alleged IRA cell. However, by the time they learn this, Helen and Walter, afraid that they were being tailed, have already gone into hiding.

With the CIA worried about an imminent attack, Annie is paired with a British MI-6 agent, James Elliot, to help track down and protect Helen and Walter. They go to Helen and Walter's apartment but they aren't there. As they look for clues into where they might have gone, an assassin shows up at the apartment, attacking Annie before Elliot is able to put him down. With one attack foiled, it's obvious that Helen and Walter have stumbled onto something big, and now it's up to Annie to find them before it's too late...