Season one of Luther introduces Chief Inspector John Luther, who returns to the police force
after several months of suspension due to having a nervous breakdown. That breakdown
came after Luther allowed an abuser named Henry Madsen to plummet to his death,
although the criminal ended up surviving and falling into a coma. This decision severely
affected Luther’s mental health, not only temporarily costing him his job, but also
ruining his marriage to his wife Zoe. As Luther tries to put his life back together and pursue
reconciliation with his wife, Zoe has already moved on and began dating a man named Mark.
Working alongside Luther is his boss, Rose Teller, the eager and loyal rookie Justin Ripley,
and Luther’s best friend, Ian Reed. Luther’s first case upon returning to work is investigating the
double homicide of a husband and wife. Luther quickly realizes that the couple’s daughter,
Alice Morgan, is the true murderer, but is unable to prove it. Alice Morgan is a genius,
narcissistic psychopath who feels proud to have evaded arrest. Luther and Alice form a
strange fascination with each other that verges on romantic, which leads to Alice
hiring women to assault Mark in the hopes of reuniting Luther and Zoe. And when Henry
Madsen awakes from his coma, Alice murders him to prevent him from testifying against Luther.
While investigating a diamond robbery, Luther discovers that Reed had allowed the robbery to
take place in exchange for a cut of the profits. Reed kills his criminal contact
and goes on the run. Resolved to kill his best friend to save himself, Reed holds Zoe hostage
to lure Luther into a trap. When Zoe fights back, Reed kills her and frames Luther for her murder.
Rose Teller believes Reed’s story and blames herself for allowing Luther back on the force,
then stages a manhunt for the disgraced detective. Meanwhile, investigator Martin Schenk has doubts
about Luther’s crimes and begins looking further into Zoe’s murder. When Teller gives a kill order
for Luther, the loyal Ripley intervenes and helps his friend escape the police.
Luther then turns to Alice Morgan for help in clearing his name and taking down Reed. The duo
team up with Zoe’s grieving boyfriend, Mark, to capture Reed and force him into giving a taped
confession. Reed begs Luther to kill him, but Luther resists the temptation and instead tries to
arrest him. When Reed then attacks Luther, Alice intervenes, holding Reed at gunpoint. When Mark
asks for Alice to kill Reed, she complies. And so, as the police arrive, Luther,
Alice, and Mark are left standing over the dead body of Detective Ian Reed.
In season 2 of Luther, John Luther is still reeling over the death of his wife,
Zoe. Luther and Justin Ripley join a new police unit called Serious and Serial led by Martin
Schenk. Working alongside them are the ambitious detective Erin Gray and technology expert
Benny Silver. Meanwhile, Alice Morgan has been institutionalized, but Luther helps her escape.
An old acquaintance from Luther’s past then asks him to save her daughter, Jenny Jones,
who has been forced into a world of drugs and prostitution. Luther saves Jenny and
develops a fatherly role toward her. When one of Jenny’s abusers comes after her,
Jenny kills him and Luther helps cover up the murder and ensure her future safety.
In season 3 of Luther, the ambitious Detective Erin Gray teams up with police superintendent
George Stark to investigate John Luther’s history of corruption and unethical methods to take down
suspects. The duo attempt to manipulate Ripley into helping them build a case against Luther, but
Ripley refuses and remains loyal to his partner. Despite the investigation, Luther is slowly
getting his personal life back on track, beginning a relationship with a woman named Mary Day.
Luther’s next case is a violent vigilante named Tom Marwood, who begins murdering criminals while
demanding justice for his wife who had been assaulted and killed four years prior. While
attempting to apprehend Marwood, the vigilante shoots and kills Ripley. Luther is absolutely
devastated over his friend’s death, and his grieving is made worse when Stark and Gray blame
him for the death and arrest him. Despite her resolve to take down Luther and his corrupt ways,
Gray begins to realize that Stark’s extreme hatred for the man has clouded his judgment,
as Luther’s love for Ripley was apparent to everyone. Fortunately, Luther still
has friends on his side. Alice Morgan returns to town and is secretly assisted by Luther’s
loyal colleagues Schenk and Benny in freeing the detective. Marwood then goes after Mary,
and as Luther pursues the killer, Stark and Gray pursue the detective. In a confrontation
with Marwood, Stark is killed and Gray is critically injured while trying to protect
Mary. Marwood then captures Mary and Alice and holds them at gunpoint, forcing Luther to
choose which of them to save. A distraught Luther chooses Mary, but before Marwood can kill Alice,
the women fight back and Alice kills the murderer. As the season comes to a close,
Mary ends her relationship with Luther and urges him to pursue Alice instead.
In season four of Luther, the titular detective is living in a self-imposed exile, retired from the
police force, grieving Ripley, and disconnected from Alice. Luther is pulled from his exile when
new Serious and Serial recruits Theo Bloom and Emma Lane pay him a visit to inform him that
Alice Morgan has been murdered. Luther returns to London to investigate Alice’s death on his own,
abducting an old school gangster named George Cornelius and torturing him for information.
Cornelius denies killing Alice, but confesses he had met her when she attempted to sell him
stolen diamonds in the hopes of using the money to run away with Luther. Cornelius
eventually escapes from Luther and puts out a bounty on the detective’s head.
Meanwhile, Schenk and his Serious and Serial squad begin investigating a cannibalistic serial killer.
When Bloom is killed during the investigation, Luther reluctantly rejoins his old unit to help
bring the killer to justice. The team discovers that the cannibal killer is a man named Steven
Rose, and Luther and Lane track him and his newest victims to an abandoned hospital. Lane kills Rose
and saves his captives, earning some small form of justice for her deceased partner, Bloom.
Luther is then visited by a mysterious woman named Megan Cantor, who claims to have received
a psychic message from the dead Alice. The message pertains to a case from early in Luther’s career
involving a young boy named Jonathan Black whose murderer was never caught. Megan’s
message points to a woman named Stacy Bell, who Luther had always suspected as Jonathan’s killer,
but never had the evidence to prove it. Luther goes to Cornelius and offers to give him all of
Alice’s stolen diamonds in exchange for the gangster to call off his bounty on Luther’s
life and a big batch of drugs. Luther plants the drugs in Stacy Bell’s apartment and then convinces
Schenk to send the police to investigate. While finding the drugs, the police also
find evidence linking Stacy to Jonathan’s death, finally bringing the killer to justice. Megan
Cantor reveals to Luther that she was a childhood friend of Jonathan’s and had spent her life since
trying to take down his killer. Realizing Luther’s connection to Alice, Cantor lied about the psychic
message to trick the detective into revisiting the years-old case. As the season comes to a close,
John Luther remains resolved to uncover the truth behind Alice Morgan’s death.
In season five of Luther, John Luther finds himself paired up with Serious and
Serial’s newest recruit, Catherine Halliday to investigate a new, violent serial killer.
Dr. Vivien Lake informs the team that she believes one of her patients, James Hauser,
could be the killer. But, it turns out, Dr. Lake’s husband, Jeremy, is the real killer,
and Dr. Lake is framing her patient to throw off the investigation. Although the husband and wife
have an agreement on how Jeremy can go about his killings, a brain tumor has caused the man
to become more violent and unstable. Eventually, Luther and Halliday arrest Dr. Lake, but Jeremy
escapes and allows his wife to take the fall for his crimes as he searches for his next victim.
As the Serious and Serial unit hunt for Jeremy Lake, Luther pulls away to focus on
his own problems. Aleister, the son of gangster George Cornelius, has been kidnapped. Cornelius
suspects that Luther might have knowledge about Aleister’s location, and sends men to beat and
torture him for answers. After escaping Cornelius’ men, Luther is paid a surprise visit by the very
much alive Alice Morgan. Alice had faked her death after killing some of Cornelius’ goons,
and is resurfacing now to put an end to George Cornelius and reunite with Luther. Alice’s return
reminds Luther of their time together, and the complicated romance that they formed. But things
can never be simple with Alice Morgan, as she murders Aleister, sending George Cornelius on a
rampage. The gangster sends a hitman named Palmer to strike Luther where it hurts, kidnapping his
lover, Alice, his friend, Mark, and his loyal co-worker, Benny. After Palmer executes Benny,
Luther makes a deal with Cornelius to stop the cycle of violence. The duo kill Palmer,
ensuring Alice and Mark’s safety, but Cornelius takes a photo of Luther standing
over the assassin’s body to use as blackmail against the detective should he ever need it.
When Alice discovers that Luther had struck a peace deal with Cornelius, she becomes furious
and seeks a sinister revenge of her own. Just as Alice attempts to murder Cornelius,
Schenk and the police arrive to arrest him, scaring Alice off. Cornelius then
shows Schenk his blackmail photo of Luther, completely incriminating the detective.
Meanwhile, Luther and Halliday finally catch the serial killer Jeremy and put an end to his reign
of terror. Knowing Schenk was preparing to arrest him, Luther asks Halliday to let him go and gather
evidence to clear his name. But before Luther can leave, Alice arrives and murders Halliday. Feeling
betrayed by Luther’s deal with Cornelius, Alice has finally snapped beyond repair.
As Schenk and the police close in on Luther, the detective chases Alice into a construction site.
As the two toxic lovers fight, Alice forces Luther to allow her to fall to her death. As
the series comes to a close, Schenk arrives at the construction site and arrests Luther. The
detective’s messy entanglement with Alice Morgan has finally led to his inevitable downfall.