The Fly Team and new Europol liaison Megan “Smitty” Garretson investigate when an American police detective on the Federal task force is murdered in Paris while looking into a U.S. company suspected of selling illegal weapons in France and the Middle East.

When a local predator begins extorting underage American girls online, the team attempts to bring the offender to justice with on-site help from one of the victims; Kellett decides she should find a roommate.

The team travels to Mallorca when an American is found brutally murdered on the estate of her powerful father-in-law.

When a former U.S. Marine is detained in Istanbul on a charge of smuggling antiquities, the Fly Team races against the clock to organize her release before the Turkish police learn the truth behind her visit

The Fly Team searches Bucharest for a Romanian surrogate who goes missing shortly before carrying the biological child of an American couple to term. Also, Forrester’s concern about the safety of his neighbors in Budapest intensifies.

Vo’s friend from the U.S. Navy calls in a favor to help find her missing nephew in Crete. Meanwhile, Forrester hangs back in Budapest to take care of personal business.

When an American businessman’s bodyguard and girlfriend are kidnapped a few feet away from him in Barcelona, the Fly Team questions if the man is as innocent as he claims. Also, Raines grows closer to Maya, the owner of the team’s favorite local bar.

Vo goes under cover when the team investigates the mysterious death of an American model in Milan; Kellett is caught off guard when Dandridge arrives looking for visibility on the case.

The team races through the streets of Budapest to put a halt to a major art heist about to be perpetrated by an American; Forrester grows angry as Dandridge watches every move the team makes.

When an American basketball player for a Lithuanian team goes into cardiac arrest, the team investigates along with Zoey McKenna, the new agent appointed by Dandridge.

The team races to find a kidnapped American teen in Austria as the clock ticks on Forrester's reassignment.

The Fly Team and Smitty reunite with Jaeger in Berlin as they all delve into a case involving an unidentified American who killed an elderly German man who appears to have been a covert asset of the ruthless Stasi in East Germany during the Cold War.

The team investigates the death of an American lawyer working out of Budapest, Hungary, after his is killed by a car bomb; Kellett begins to grow close to Hungarian lieutenant Benedek Erdős as the critical case progresses.

The team and Smitty head to Morocco when a commercial aircraft flying from New York to Athens is grounded and an American citizen on board goes missing; Kellett's relationship with Erdős continues to blossom.

The Fly Team lends a helping hand to the Hungarian National Police when one of their police officers is accused of murdering a couple in Budapest; Kellett questions her relationship with Erdős.

The Fly Team heads to Vienna to find the culprit of an acid attack on a rising American prima ballerina. Also, Smitty receives some troubling intel from a familiar face.

The team jumps into action to protect Forrester when a Russian hit man seeks revenge on him; Raines is sent into a tailspin when someone close to him is taken.

After an American tourist is killed while visiting Stockholm with his girlfriend, the Fly Team must work together to take down a Swedish group responsible for the hate crime.

After a cybersecurity expert robs one of Switzerland's largest and most secretive banks, the Fly Team is called to track down the fugitive. Also, Smitty's loyalty is put to the test.

The Fly Team jets off to Portugal when the daughter of a prominent American hotelier becomes the primary suspect in the murder of an employee. Also, Raines becomes concerned about Vo.

When a Russian missile is stolen and put on the black market in Budapest, the Fly Team must secure the weapon before a mysterious American arms broker delivers it into the wrong hands.