When Wayne goes missing on the day of Nikki & Mike's wedding, the joyous festivities are put on hold as Jason and the MPU race to locate her and finally bring down Inspector Braun and his connection to the car bombing murders.

The MPU is on the case when a young boy claims his father was abducted by aliens as they were stargazing at a remote campsite. Jason and Nikki enlist Mike's help in getting access to Braun's computer files. Kemi and Helen partner up and venture out into the field.

When a customs broker goes missing, MPU discovers that she is an undercover FBI informant now being forced to transport a little girl over the border to her criminal father. Jason and Mike find a tablet at the girl's last known location, and defying the FBI's orders while working alongside Lt. Gabrielle Bennett, Jason goes undercover in order to rescue both the customs broker and the girl.

When a young woman is kidnapped and locked away to freeze to death, the MPU suspects her boyfriend or his father might know more than they're letting on. Meanwhile, Wayne uses her connections to try and get a job at the MPU, and Kemi is put in a dangerous situation while on the case.

The MPU searches for a kidnapped tough-as-nails neighborhood watch captain. Jason enlists Wayne's help investigating the car bombing. Mike is concerned Nikki is keeping secrets from him.

As the MPU moves into new offices, which comes with new boss Inspector Hollis Braun, a call comes in reporting the disappearance of an entire city bus full of students on a field trip. The team utilizes a father who tried to stop the kidnapping, as Jason reaches out to an old colleague for assistance in the search.

When Violet, a psychiatric patient, escapes her facility, Jason and Mike are shocked to find a letter from Jason and Nikki's daughter Sidney among her belongings. Mike and Jason go to her halfway house, they realize that she has been off her medication for days and are now concerned for her safety. Meanwhile, Helen takes her new relationship to the next level.

When a bride goes missing on her wedding day, Mike and Kemi discover the woman was living a deceptive life. Meanwhile, the mystery surrounding Keith's disappearance starts to unravel as he tells Jason and Nikki more details about his time in captivity and leads them to a cabin where they find a horrifying scene.

A young pregnant woman goes missing one day before her emergency c-section and the adopting mother turns to the MPU to locate her before the baby's life is risked. Meanwhile Jason digs deeper in the car bombing case and meets a disapproving Braun.

The MPU is on the case when a young hockey player goes missing during a fight with an opponent on the ice. Kemi is unexpectedly reunited with a face from the past. Nikki runs interference with Braun when Jason dives deeper into the car bombing murders.

When a limousine filled with teenagers, including a Senator's son, is hijacked on the way to prom, MPU discovers that the ex-girlfriend of one of the victims may have been the actual target. Now, Jason, Mike and the team must race to the prom in order to save the girl before it's too late.

The MPU searches for a Benjamin Franklin aficionado after he suspiciously disappears during one of his city tours. Meanwhile, a new forensic scientist is hired and the team attempts to manage her over-eager working style. Jason and Mike try to bond as new partners.

The MPU searches for a homeless female teen that disappeared after running away from home and living in Philly's Gayborhood. Kemi is hit especially hard as the team races to find and rescue the missing teen. Jason and Nikki spar over his continued investigation into the car bombing.

A popular travel influencer goes missing and the MPU race to find her as a hurricane rages and a state of emergency is declared. Mike and Wayne get closer as Helen connects with someone unexpectedly in the aftermath of Nikki's bachelorette party.

After a collegiate women’s rowing team goes missing during morning practice on the river, MPU deduce that their boat was sabotaged. When Kemi finds evidence connecting one of the girls to Irish mob boss, Charlie McGannon, Nikki confronts him as Jason and Mike interrogate a rival Polish mobster who may have intel on the girls location. Meanwhile, Jason explores his fear of commitment with Wayne, who’s now paroled.

When an Army Lieutenant, and the wife of Houston’s old Army buddy, is kidnapped, MPU suspects a Major who the victim had reported for harassing women at the base. However, Jason and Mike learn that the victim and her husband were having marital and financial issues, leading them to uncover a dangerous and deadly weapons trade.

Sidney, upset that Jason and Nikki don't believe her claims about Keith, comes clean about the details surrounding the day of his disappearance, causing Jason to cast serious doubt on the boy claiming to be his son. Meanwhile, Mike's police mentor brings a missing officer's case to the MPU team.

As the MPU struggle to adjust in the wake of tragedy, they are forced to jump into action when a muralist goes missing after painting a piece on a local rooftop; the missing person's mother reveals that he was scheduled to donate his rare bone marrow to his dying brother, who needs surgery within the next 48 hours in order to survive.

An accomplished playwright is kidnapped prior to a local theatre's grand reopening. MPU discovers that the victim and her partner had received a video threat ordering them to shut down the troubled theater, which had previously been severely damaged in a fire decades earlier killing 87, or the playwright will be burned to death. Meanwhile, Jason asks Wayne to track down who's the father of Sidney's baby.

Jason and Nikki utilize a twin sister when a missing person case turns into a possible murder investigation. Meanwhile, Kemi helps C with his dating life and Keith gets reckless.

Mike is taken back to his first unsolved case when the remains of an Amish man surface seven years after his murder. After he reconnects with the man's family, the wife of the man mysteriously goes missing, prompting a massive search and disclosing a web of deceit.

When Nikki suddenly goes missing, MPU bands together and discovers that Raina, a criminal who Nikki put away, has escaped and is out for vengeance.

The MPU works to track down the kidnapped son of a doctor, but the case takes a turn when his mother gets in direct contact with the kidnapper. Meanwhile, Kemi expresses her concerns for Sidney's wellbeing to Nikki and Jason.

When a brewery foreman is kidnapped after arguing with his CEO over safety violations, MPU finds evidence that suggests that the victim was taken by competitors over a stolen beer formula. Also, Bennett’s ex, who is also Houston’s step-son, threatens to make her life hell for interrogating his client without representation.

A foster care worker is reported as missing, but after he ends his own life, the MPU starts to investigate a pregnant woman he was seen with who has been missing for two years. Meanwhile, Sidney follows Keith and fears he may be dangerous.