Goren and Eames investigate the death of Heidi Conington, a former ambassador's daughter, and then the similar murder of Jenna Shea not long after, interviewing her roommate Jo Gage. Jo's father turns out to be Goren's former mentor, Dr. Declan Gage, who tries to convince Goren that the killer is Sebastian, the one killer that he has never been able to capture or forget. Ross warns Goren that he doesn't want Gage, who betrayed his entire team in the original Sebastian investigation, anywhere near the case. When Eames is taken from her home, suspicion turns to Gage, especially after some of her belongings are found in his possession, but when Eames saves herself, she can't give the police any clues to her captor.

Logan and Wheeler investigate the death of a womanising doctor, which leads directly to his son's relationship with a teacher.

Goren and Eames investigate after Ashley Gardela, a fellow officer's teenaged step-daughter, is found dead in her car after a night of partying, which leads them to her boss (Jason Raines), an ex-boyfriend with a record (Brian Murphy), and the boss's wife (Kelly Sloane-Raines). After another supposed young lover comes forward, Goren and Eames focus their investigation away from Jason Raines and toward another source. [ Recap available. ]

Logan and Wheeler investigate when fireman Ian Duffy is stabbed twenty-two times before driving himself to the fire station and collapsing. When the investigation leads to questions concerning Duffy's sexual preference, Logan and Wheeler end up in the middle of a brawl with the other firemen that leads to an official investigation and a secret involving Duffy's wife, his friend Brendan Keele, and a crime that someone else confessed to years earlier.

Goren and Eames investigate the death of a well-known and well-liked historian, Dr. Adlai Copeland, and their investigation leads them to suspect the victim's brother Ted, who was perpetually short of money and had recently been cut off by his brother. Ted is the prime suspect in the investigation until he, too, turns up dead, and detectives then turn their eye to the victims' wives, both of whom had something to gain from the two mens' deaths.

Goren and Eames head to Vietnam to pick up Simon Henry Fife, who has recently confessed to the 1992 murder of ten-year-old actress Amberleigh Harner. Both Goren and Eames have trouble believing what Fife has to say, and it isn't long before Goren manages to find holes in Fife's story. Eames and Goren have twenty-four hours to look into the murder and turn their attention to the original investigation, contacting the original officer on the scene. Their investigation leads them to believe that the suspect may be much closer to home than anyone thought.

The death of a music producer is initially believed to be connected to his professional interests, but later the attention turns to his romantic interests.

Ross, Goren and Eames are called in on Thanksgiving when Amanda Dockerty, the daughter of the first deputy commissioner of the NYPD, goes missing while on leave from the army. The investigation into her disappearance soon turns into a murder case when Amanda's body is found, but Goren's mind is anywhere but on his job as he struggles to deal with a personal crisis concerning his mother.

When the body of former teen star Alvin Stevens is found buried in Potter's Field, Logan and Wheeler try to find out who would have motive to murder the young man that Wheeler's generation affectionately remembers as lovable geek Skater. Their investigation soon leads them to bootleg DVDs, the Albanian mob, and another child star who never moved on with his life.

After popular on-line vlogger Willow is kidnapped during a live broadcast, Logan and Wheeler investigate the crime that they doubt may have ever occurred. As they attempt to track down the real identities of Willow, her boyfriend Holden, and the kidnappers, someone ups the ante by asking for an online ransom for the couple, demanding fans go to a website to save the duo. The investigation takes a turn when a former classmate of Holden's shares a screenplay he wrote about a cyberkidnapping that is eerily similar to the weepingwillow17 saga.

The murder of a pregnant young Muslim-Pakistani woman with the message '4 911' leads Logan and Wheeler to investigate the child's Italian-American father and the animosity between their families.

Goren and Eames investigate when Isabel Harrington is found murdered in her apartment, and while their investigation initially leads them to the married father of her 18-month-old daughter, they soon begin to look more closely at her family -- invalid grandmother, wastrel father, young step-mother and weak half-uncle.

A candidate for the next mayor of New York could see her election hopes dashed when Goren and Eames investigate her husband on suspicion of murder.

After Fulla T, a local rapper who was encouraging his fans to report crimes when they heard about them, is murdered outside a radio station, Logan and Wheeler find themselves reluctantly partnered up with Harry Williams, a detective from the gang unit. Wheeler is willing to give Williams the benefit of the doubt, but when their witness begin to turn up dead or missing not long after Williams learns they're looking for them, Logan begins to wonder just what side of the law Williams is really on.

Goren and Eames investigate the murder of a well-known televangelist's wife after a rally, but Goren is preoccupied with dealing with his mother's medical condition and the reappearance of his long-lost brother.

"30" is a sixth season episode of the television series Law & Order: Criminal Intent.

Logan and Wheeler investigate when a judge's son is murdered shortly after a rapper is sentenced in the judge's courtroom, but soon realise that his friends may be more closely linked to his death than the rapper.

Goren and Eames investigate when a doctor who had testified in a case involving the deaf and controversial cochlear implants is murdered, and find themselves teaming up with a detective who interprets for the deaf as they try to get answers in a case where no one seems willing to communicate with them.

Suspicion turns to a married astronaut after his lover is found murdered.

A woman who married a billionaire winds up dead under mysterious circumstances shortly after her son dies.

Goren and Eames find a scrapbook belonging to a serial killer on death row. It suggests that he may have had more victims than previously known.

Logan and Wheeler investigate the death of a police recruit. Logan becomes distracted by the death of his neighbor and Eames steps in to assist Wheeler in the investigation.