It's a sink-or-swim mission when Luke and the team dive into deadly waters to stop a sinister terrorist from making a massive splash.

With his retirement from the CIA imminent, Luke prepares for his next adventure, but revelations at home and an urgent matter at work upend his plans.

Forced to team up in order to take down Boro, Luke and Emma realize their newly strained relationship is only the start of their problems.

After receiving reassurance from Luke, Emma comes home to a startling surprise. In Greece, the team takes on a risky mission to break out a trusted ally.

Amid a devastating family emergency, Luke finds the lines of his double life becoming blurry as he deals with a distracted Emma and a demanding Boro.

While closing in on Boro, Luke and Emma juggle relationship drama and a highly delicate situation. A life-or-death matter forces Roo to find a release.

Barry and Tina infiltrate a private, high-stakes card game in hopes of inching closer to Boro. Emotions boil over when the team gets trapped in a bunker.

A face from the past threatens Luke and Tally's recharged romance. The team breaches a fortified compound to keep vital intel out of enemy hands.

The team goes from averting an international crisis to seeking sensitive intel in Moldova, where Emma offers to lure a target when complications arise.

While Cress tightens the screws, Chips matches wits with an interrogation expert. A stealth mission makes a bigger bang than expected.

With the clock ticking, Luke and Emma make tough choices to finish the mission and stay alive. A big day for the Brunner family spirals out of control.

As Greta attempts to loosen Luke's lips, the safe-house gang gets an earful from afar. Emma turns heads on the dance floor with an unlikely date.

Barry hitches a ride to the final frontier. As an operative's cover story begins to crumble, Luke and Emma seek help from an unexpected ally.

Emma and Luke catch a buzz in a deep-sea submersible. Back on land, bullets and breadsticks fly in a confrontation at a pizza joint.

Every second counts as the team scrambles by land, air and sea to avert a catastrophe. Aldon finds himself outnumbered — but not outmatched.

As the clock ticks down to zero hour, Luke and the crew must break into a top-secret facility before their adversary turns off the lights — for good.