Booker has a revelation about Officer Tower's shooting and puts his career on the line to prove Hanson's innocence. Ioki remains comatose.
During the investigation of a series of beatings at a college sports bar, Hanson and Penhall uncover a major bookmaking operation. Hoffs, Ioki and Penhall take the detectives' exam.
While undercover investigating a drive-by shooting death of a student at a chaotic crime-infested school, Pennhall and Hoffs begin to question the tactics being used by the new principal to bring order to the student body.
While attempting to track down a serial arsonist at a high school during Halloween season, the Jump Street team becomes thoroughly spooked following the accurate premonitions of a self-proclaimed teenage psychic.
Hanson, Penhall, and Ioki go undercover to stop a group of spoiled rich kids who burglarize houses, toy with poorly-trained private security officers, and engage in reckless activities for kicks. Ioki's flashbacks begin to affect his work.
Hoffs is date-raped by a classmate while investigating a drug ring at a prestigious medical school. The rest of the Jump Street team rallies around her to help bring the perpetrator, who claims she seduced him, to justice.
The aftermath following the murder of a high school teacher's wife is shown from the perspective of the student who was hired to kill her, while Hanson and Penhall work undercover at the school to solve the case.
Suspecting the murder of a motorcycle enthusiast is linked to the corrupt businessman Raymond Crane, who was also behind the framing of Officer Hanson and near-fatal shooting of Officer Ioki, Booker uses blackmail to gain entry into Crane's organization, where he hopes to gather the evidence needed to finally bring Crane to justice.moreless
Having failed to bring down Crane on his own, Books enlists the help of his former Jump Street colleagues to pose as bikers to find proof Crane was responsible for the death of Mickey Maxwell.
On a long-term stakeout at a vacant house to gather evidence on a family living across the street suspected of running a burglary ring, Hoffs becomes preoccupied with the welfare of the family living in the neighboring house, who she suspects is living in an abusive situation. Fuller opens up to Hoffs about a dark family secret.moreless
Ioki is forced to revisit painful memories from three years earlier when he is held at gunpoint by a young man whose life was left in shambles after Ioki convinced him to turn in his drug abusing parents.
A group of over-achieving college students are suspected of using the chemistry lab to create synthetic heroin and testing it on unsuspecting junkies; Ioki helps a Chinese student who is being threatened by a government operative for being linked to the Tiananmen Square protests; Hoffs is dogged by an unwanted suitor.moreless
Investigating the murder of a popular female teacher and environmental activist, Hoffs befriends a sexually-confused student who may have witnessed the act; A young teaching-intern's attempted seduction of Fuller, who's posing as a sex education teacher, sends him into a mid-life crisis.
Fifty years in the future, a young cop hoping to revive the Jump Street program interviews the retired officers who were there when it all started.
On the day of his execution, Ronnie Seebok recalls the events that lead up to him being condemned to death row as Hanson tries to convince him to appear in a film to deter youth in his old neighborhood from a life of crime.
Hanson and Penhall find a way to get out of the cold while remaining on the job as they trail a communist radical suspected of bombing a school newspaper to Florida during spring break.
Penhall and Hanson link up with a CIA operative on their extremely dangerous quest to find Penhall's wife in war-torn El Salvador.
Donning their McQuaid brother aliases for one last time to ferret out a high school thief, Penhall suspects a 22-year-old student who is faking his age for unexpected reasons, while Hanson befriends a teenage girl who has kidnapped her baby sister. Penhall adjusts to his role as Clavo's guardian.
Fuller is hesitant to let a handicapped policewoman accompany Hoffs undercover to catch a rapist who targets disabled college women.
Hoffs and Ioki find their professionalism tested when they are assigned to infiltrate a protest group suspected of killing the leader of a Neo-Nazi organization, while Penhall poses as a Nazi to determine if the new leader is planning a violent reprisal.
Following their thwarting of an "assassination" attempt of a senator giving a speech at a high school, each Jump Street cop (plus Blowfish) relates his or her own Hollywood-inspired version of the events to a reporter interested in turning the story into a movie script.
Blowfish talks Penhall into becoming his son's Little League coach. He soon discovers that the team's best player, who has befriended Clavo, is pictured on a milk carton as a kidnapping victim.
Penhall abandons Ioki during a stakeout when he learns that Clavo has been taken to the hospital. As punishment, he is assigned to foot patrol in a precinct full of dirty cops and partners with rookie officer Dean Garrett, who the other cops suspect of being an IAD plant.
While investigating the gang rape of a jogger, Hoffs, Hanson and Penhall find themselves at the mercy of the same group of student suspects, who try to instigate a riot while a school is cut off from the outside world during a storm.