When an American student and sex worker is murdered in Budapest, similarities to a recent case in Japan lead the Fly Team to partner with detectives from Tokyo.

When the star witness in the case against Greg Csonka, the man responsible for the death of Wes' former partner, is beaten to death in a Budapest prison before he can testify, the Fly Team attempts to salvage the case to secure Csonka's conviction.

After a young American woman is brutally murdered in Venice, the Fly Team is met with hostility when they discover that their person of interest has ties to a well-connected Italian family. Soon, the case gets even more complicated when the CIA Station Chief shows up with an agenda of his own. Meanwhile, pressure mounts on Quinn to deliver intel on Mitchell.

When a Russian biochemist is assassinated for trying to defect with his highly sensitive biotoxins research, the Fly Team springs into action to protect his daughter, whose father’s last wish was that she get his research to a trusted American microbiologist. Meanwhile, Mitchell stays behind to help Vo during her recovery, and Booth clashes with Smitty when he finds out she could jeopardize his promotion.

When an American student is found dead at a prestigious UK university, the Fly Team investigates an infamous secret society. Smitty’s personal history with the school comes to a head when she’s confronted with the same old-world elitism.

When a televangelist on the FBI’s most wanted list surfaces in Gibraltar to seek asylum, the Fly Team’s attempts to take him down hit a roadblock as they face political stonewalling upon arrival to the region. When the predatory preacher goes after the daughter of a disciple as his next target, the team must abandon protocol to intervene.

After an American CEO living in Prague is extorted for millions in cryptocurrency and his family is kidnapped, Mitchell receives a surprise visit from his ex-girlfriend, FBI Special Agent Ella Driscoll, who wants the Fly Team’s help on the case.

The Fly Team heads to the country of Georgia to determine the motive behind an attack that targeted two American soldiers at a NATO-Georgia joint training center before it turns into an international incident. Meanwhile, a supervisory position opens in another FBI division in Europe, and Mitchell encourages both Vo and Raines to apply.

When an American official in charge of a high-profile three-way prisoner swap in Belgrade is detained in Romania, he requests the Fly Team step in and carry out the exchange. When their convoy is attacked and one of the prisoners escapes, the team must do everything in their power to find the missing prisoner before the highly sensitive mission is compromised.

When an American teenager disappears from a beach party during her senior year trip to Portugal, the Fly Team heads up the search, which is further complicated by the missing teen's parents' differing opinions.

The deputy inspector general calls on Tate, who is fluent in Spanish, to take on her first undercover field mission, joining Wes and the team in Spain as they investigate a seemingly dirty U.S. Drug Enforcement Administration special agent working out of Madrid.

A member of the Fly Team goes missing as the hunt for Greg Csonka continues in Paris. Meanwhile, Vo’s life hangs in the balance after being shot.

When an American businessman is gunned down in Bratislava, the Fly Team must work with an unscrupulous local detective while safeguarding the sole witness, a fearful tourist from Wisconsin being held by police. Meanwhile, Quinn begins to feel pressure from her brother to deliver information on Mitchell.

When a suspected American arms dealer with a lengthy rap sheet pops up in Vienna with stolen weapons, the Fly Team sends Mitchell and Smitty undercover to try to infiltrate his operation. During the mission, Smitty enters muddy waters while working with the suspect’s wife. Meanwhile, Mitchell’s biological father shows up in Budapest after being released from prison to seek him out despite Mitchell’s disinterest.

When a U.S. ambassador is taken hostage at a TV station in the Netherlands alongside 70 civilians, the Fly Team is forced to work quickly to find out who they're up against. Meanwhile, Wes works to earn the respect of his new team.

The Fly Team leads an international manhunt when an American woman and her new husband flee from Baltimore to Istanbul with her young son after a heinous murder. Also, Vo partners up with Special Agent Riley Quinn, who was not only sent to Budapest to work her first big case alongside The Fly Team but to also clandestinely investigate a member of the team.

When an American man is kidnapped in Warsaw alongside a Ukrainian woman he met on a dating site, the Fly Team heads to Poland to track down the mastermind behind the site.

Wes' former colleague, U.S.-based agent Tyler Booth, enlists the Fly Team's assistance in helping him capture an American on the FBI's "Most Wanted" list by luring him out of Russia with the help of the perp's conflicted ex-wife.

When a psychologist with national security intel goes missing on a hike in the Swiss Alps, the Fly Team works alongside a friendly face, Agent Tyler Booth, to find him. Meanwhile, Mitchell receives unnerving news regarding his biological father.

The Fly Team meets Supervisory Special Agent Wesley "Wes" Mitchell when his partner is shot in LA and the suspects flee to Budapest, sending Mitchell overseas.

When a bus full of American volunteers is hijacked in a dangerous section of Morocco, the Fly Team works to locate the missing aid workers and the people who kidnapped them.

The Fly Team discovers they’re on the trail of a serial killer, taking the investigation, and Mitchell, to Japan to put an end to the international killing spree.