In the Season 3 finale, unable to trust anyone in New Orleans, the team calls in FBI Assistant Director Isler to help expose and stop the sinister scheme that Mayor Hamilton has planned for the residents of Clearwater.
Pride finds a connection between Mayor Hamilton and the illegal activity taking place in the city of Clearwater after the Belle Chase Navy Chaplain and pastor at Clearwater Baptist is murdered. Meanwhile, Percy continues to face repercussions of her choices on a previous case
After the team uncover a link between an international drug ring and the police department, Lasalle must investigate his former partner. Meanwhile, Pride worries about Rita's safety as she looks into a connection between the mayor and illegal activity in Clearwater.
While investigating a deadly accident at a naval base, the team discover that a unit of Seabees was poisoned with a contagious super virus, leaving the rest of the base and the entire city of New Orleans at risk for a catastrophic outbreak. Meanwhile, Wade is infected with the virus during an autopsy and given hours to live if an antidote can't be found.
Pride investigates a murder on a deep-sea-oil rig, where the team discover a dangerous gas leak that threatens to cause a catastrophic explosion. Elsewhere, Sebastian begins his special-agent training at FLETC.
The team suspect foul play when a Marine corporal and amateur race-car driver is involved in a fatal crash. Elsewhere, the U.S. Attorney's office gathers evidence for a Grand Jury indictment appeal in the Garcia case that would extricate the cartel from the city.
A Navy Seal candidate who was murdered just before his graduation leads the team to investigate unorthodox training exercises. Meanwhile, Wade asks Pride for advice after her adopted son announces his own plan to join the Navy.
In the third-season premiere, the team join forces with other federal agencies to track down a sniper targeting crowded areas of the city. Meanwhile, an FBI special agent begins investigating Pride and the NCIS team.