With the situation mounting in Iran, getting back to Luxembourg looks grim as John struggles to adjust to life and work in Milwaukee, while a driven homicide detective begins to build her case.

Homicide Detective Agathe Albans arrives in Milwaukee to interview Dennis. John must make a desperate last minute push to remain on the travel team.

After a helicopter crash changes the stakes of a foreign election, a former-intelligence officer for the U.S. State Department has to choose between returning to the line of duty in order to dismantle a dangerous political movement in a war torn country as a matter of national security or his personal obligations as the head of a young family.

John acts against standard protocol, which alerts adversaries of his whereabouts and necessitates the abandonment of the John Lakeman cover identity, jeopardizing all.

John returns to Milwaukee a person of interest in Agathe's investigation, while his already fragile mental state worsens. At McMillan, Stephen's recovery and a sudden promotion further jeopardize the mission.

Drunk and stoned, John breaks into Cantar Walley's compound. Alice considers the cost of betraying her father-in-law in order to protect her husband. In the meantime, Agathe finds a powerful new ally.

John must make a choice at the train platform - be free from his obligations and adversaries by letting Agathe take the money or pursue her in an effort to protect his brother, father, and country.

Recent events tell a story that could reveal John's plan to assassinate Cantar Walley, so John takes preemptive measures, risking himself to divert attentions and create the illusion that the story is over.

Edward's captor is revealed. John prepared for a dangerous act in his first step toward the assassination of Cantar Walley, just as Walley's elite security team arrives in Paris.

An unexpected day off provides the opportunity for a last-minute bachelor party. Collective inebriation follows. John fully embraces the celebration with his wife and friends until the time line for his mission abruptly moves up.

In Luxembourg, Leslie attempts to set John up for failure by increasing his workload just as John's real job requires immediate and critical action. An old friend arrives and further complicates John's life.

John's effort to retrieve evidence brings him dangerously close to Agathe. Tom arrives in Luxembourg to help John catch his breath only to ask more of him.

Agathe's case against John begins to mount while John undertakes a desperate attempt to get his father's plan back on track. Meanwhile, Leslie's hostility toward John reaches new heights.

Agathe interrogates John just as Edward struggles to establish his brother's alibi. A surprise visitor joins the McMillan duck hunt in a last minute appeal to Leslie to allow John back on the travel team.

John returns to Luxembourg where his dedication to his father is put to the test, just as Agathe gathers final evidence that may allow her to learn the truth about John.

John gets closer to completing his perilous assignment, only to have matters jeopardized by a childhood mistake. Friends get involved in an unprecedented and gravely consequential way.

All hell breaks loose.

Agathe, headed back to Milwaukee to investigate John, crosses paths with Alice. Tom receives critical new intelligence that may give him the upper hand in his plan to influence the Iranian election.