The Viking army attacks Paris as the city musters its forces for defense.
The populace of Paris is in a panic after the appearance of the Viking fleet, and Emperor Charles, at the behest of his daughter, announces he'll remain in the city.
After a suspected pedophile is found brutally beaten, Andy finds out that Marlo has been conducting an unauthorized investigation into the man. Swarek insists that Andy cover for Marlo. A major drug sweep takes an unanticipated turn when Swarek deviates from the investigation to help Marlo.moreless
Longworth investigates which imaginary solider killed another Civil War re-enactment participant. Callie makes an awful discovery. Jim gets some ominous news for Callie and Jeff.
Frank and Noelle's wedding is here, but first 15 Division must find the robbers who held up a casino-bound bus full of seniors citizens. Later, preparations are amiss when Traci can't find the bride. Andy and Nick share a strangely intimate moment.moreless
The killer: pediatric surgeon Dr. Monika Harper; the victim: news shop owner and ex-military man Hank Cousineau.
Hank is found in the back of his store, dead from having his throat slit. The investigation first centers on a group of young thugs who were trying to extort money from the store owners. Then, the detectives have a look at Hank's camera, which contains dozens of photos of Dr. Monika Harper and her husband and child. They decide to look deeper into Monika's past and discover a secret she has been hiding all her life.
Josh has an important question to ask Nora. Sally's condition worsens and Aidan tells Kat that it isn't a good idea for them to see each other.
Sally is decomposing and turns to her boyfriend for help, Aidan is kidnapped, and Josh and Nora take their relationship to the next level.
Team One continues the hunt for a bomber at large as team members, joined by EMS and the military, split up to deal with multiple bomb threats in a city already plunged into chaos.moreless
Team One faces the most challenging call of their careers when a series of bombs tears the city apart.
Team One is called in when an Emotionally Disturbed Person kidnaps his neighbor's baby, thinking it's his own daughter, and takes refuge on a ferry. Ed recounts the incident to a psychologist, as he desperately tries to find out whether being the constable that kills the subject when all other options are exhausted, makes him a monster.moreless
A senator is abducted during a bomb hoax and Team One discovers that the kidnappers are two farmers who want revenge against the senator when he plans on turing their land into an airport.moreless
Ed and Greg's sons come for a ride along and disobey a direct order from Sergeant Parker when he tells them to remain in the truck while Team One deals with an incident between three cops on an off-the-books mission to clean up the streets.moreless
Jules and Sam receive some personal news, but don't know whether to share it with the team. While the SRU is called in to stop some ex-soldiers robbing an armored truck with millions of dollars, they learn more about the background of the group leader who tries to maintain a place for ex-army men and women with nowhere to go.moreless
The team tries to help a young man with amazing memory who is taken hostage to help get to a weapon with "smart" bullets which can shoot a target even behind cover. The situation gets complicated when Ed himself is taken hostage.moreless
The team is called in when a car bomb explodes at a kid's birthday party. As it turns out the victim of the explosion was the head of a local biker community which is already under investigation. The team now has to protect the young CI who is trying to find out more about the next targets while handling the female detective involved in the case.moreless
Team One's efforts to save a kidnapped woman's life are dependent in large part on the abductor's brother, who holds a dark family secret. Meanwhile, a reluctant Ed is asked to meet with the mother of a teenage girl who was killed by Ed in the line of duty.moreless
Team One has to rescue a doctor, but as they search Sam discovers a child in critical need of medical attention, and realizes that being taken hostage may be the only way to save him.moreless
Team One is looking for an armed and abusive man who has tracked down his ex-wife demanding to know where their daughter, who is celebrating her 18th birthday, is. The situation escalates when he drags his ex-wife to near the edge of a hotel rooftop, where Ed and the rest of the team face a huge moral dilemma. The dramatic conclusion leaves Team One questioning themselves, each other and even their jobs.moreless
Jim is forced to work with his former FDLE partner, convicted murderer Mike Ogletree, when a woman who came forward to clear a death row inmate is murdered. Florida's Attorney General has decided to go after the IRS agent who handled Callie's audit and they want her testimony. Although Callie is reluctant to take time off from work, she gets some supportive help from Miranda.moreless
A break is finally achieved in Sarah Holy case when Mitch, Ray, Tammy and Abby put all their information together and discover that Noble Insurance, under the direction of Kevin Stack, is systematically killing terminally ill patients in order to save insurance money and that Sarah, using her medical training, is the one who commits the murders. Mitch asks for a meeting with Sarah to confront her with what he knows.
Meanwhile, Mitch's first paying client, Gerald Sykes, is in jail charged in an ABM robbery and shooting. Despite DNA evidence, Gerald protests his innocence claiming he was not there. When Mitch tells him that he needs a viable defense, Gerald changes his initial story to claiming he was there but was the victim, not the robber.
A fire captain who feels nothing he does is good enough is given the chance to prove to himself and to an injured member of his crew that he can set things right.
Meanwhile, Greg Parker is still considering his decision to remain leader of Team One and doubts himself even more after his decision to allow the fire captain to return to the hospital to be with his injured friend has dire consequences.moreless
Team One is called in to try and stop a conflict at a psychiatric hospital where a stabbing has just taken place. In the commotion of subduing the stabber, the victim escapes from the infirmary taking one of the staff as hostage. They now have to deal with that patient, who has a history of violence and arms himself, and who wants to settle something with his best friend.moreless
When stadium security guard Gil Collins defies Sgt. Parker and risks his own life by taking a hostage situation into his own hands, he complicates matters and draws Team One into a complex situation where nothing, especially his motive, is a it first seems.moreless
As Donna gets ready to walk down the aisle, things changed drastically. Donna learns some surprising news regarding a mentor she once worked with. Now Team One, with Donna's help, must try to keep the people close to her from getting killed and make sure Donna's emotions don't get in the way.moreless
Ex-cons take hostages, forcing Callie's hospital on lockdown. Longworth and Callie must work together to keep everyone safe but things don't go as planned.
Team One is out to capture a man, accused of murdering his daughter, after he escapes from a prisoner transport. Team One learns the suspect is after someone surprising who he hopes can prove his innocence.
Ed gets word that his wife is on the way to the hospital due to complications from her pregnancy.