Lois Lane and the Daily Planet
71 episodes of Smallville carry this thread, 2d 23h in all — 17 of them are in The Essentials.
Arc membership is derived from each episode's own summary text, gated to the seasons the sources place each arc in. It shows where a thread is foregrounded, not every episode it touches.
In airing order

Lois Lane arrives in town to investigate her cousin Chloe's death and discovers an amnesiac Clark in a cornfield after she veers off the road during a storm. Lois takes him to the hospital and meets Martha, who's busy keeping watch over a severely injured Jonathan. Elsewhere, Lana finds a new beau in Paris; Clark discovers a new superpower; and Lex needs blood treatments to help keep him alive.

Lois and Clark go to the safe house to investigate Chloe's death and end up running from military men. Later, Lois returns to her cousin's grave and discovers her casket is empty, but she has little time to react before she's attacked by an unusual being.

Clark tries out for football again and learns that Jason is the new assistant coach---but Clark doesn't know Jason is also Lana's boyfriend. Meanwhile, a student gets a bizarre makeover with a dangerous side effect that gives her the power to alter the way others see themselves; Lois enrolls at Smallville High for a semester after she finds out she's a few credits shy of graduating; and Martha takes a managing job at the Talon.

Lana, Lois and Chloe are possessed by the spirits of witches who were burned at the stake in the 17th century. Later, the girls crash a surprise party for Chloe at the Kent farm and use a spell to turn the event into a raucous affair. Making matters worse, a Princeton recruiter visits Clark the night of the party.

Lois is arrested for severely injuring a Metropolis University football player who harassed her. Meanwhile, Clark visits the school on a recruiting trip and discovers scandalous activity involving the team; Jason takes Lex up on his job offer, which entails spying on Lana and Genevieve.

Clark takes in a dog with superpowers after Lois accidentally hits the pooch with her car. While looking for its owner, he discovers the dog was part of a LuthorCorp experiment and was being used to commit crimes. Elsewhere, Genevieve is revealed to be the person who helped free Lionel from prison.

Lois's younger sister, Lucy, arrives in town, and Clark learns that she has a shady past when he catches her stealing money from the Talon's register. Also, the ancient stone is taken from Lana's apartment, and Jason suspects Lionel.

The town is evacuated on graduation day in preparation for an impending meteor shower, and Jor-El warns Clark that the entire planet is in danger if the three sacred stones aren't reunited.

Lana pledges a sorority, unaware that its members are vampires. Elsewhere, Chloe sets out to impress the Daily Planet's editor-in-chief; and Lex threatens to have Prof. Fine fired if he continues to research LuthorCorp.

When a young girl's body is found hidden behind a wall of the Talon, Chloe begins acting weird and Lois goes on the trail of the girl's murderer, who turns out to be a serial killer who has been preying on Smallville girls for 10 years.

Clark is imprisoned in the Phantom Zone, deprived of his powers. Meanwhile, Lex/Zod keeps Lana captive so she can sire him an heir; Lois and Martha crash near the Fortress of Solitude, where Jor-El tells Martha how to kill Zod; and Chloe reunites with Jimmy Olsen.

Clark thinks he's developed a cold, but it turns out to be a symptom of a new superpower; Lois gets a job at the Inquisitor, a local tabloid; Lana moves in with Lex, who suspects someone is stalking him.

A guilt-ridden Lex throws a charity ball for the town and hires the All-American Rejects to perform; Clark and Chloe pursue a creature who uses male human bodies to spawn, and the hunt intensifies after the creature abducts Jimmy Olsen; Lois reluctantly agrees to go with Oliver Queen to Lex's ball.

The Green Arrow draws the attention of Lois after she sees him steal a rare diamond necklace off Martha's neck; Clark discovers Oliver Queen's secret; Lex mends fences with his father to test Lana's loyalty.

The Planet's gossip columnist, Linda Lake, makes life miserable for Lana, Lex, Chloe and Clark; Lois begins to suspect a connection between Oliver and the Green Arrow; and Lex drops a bombshell on Clark.

It's Valentine's Day in Smallville, where love blooms and hearts are broken, but not for the usual reasons---red kryptonite is infused into cosmetics, and that makes Lois and Clark a little crazy.

A Zoner called Titan turns up in a secret fight club that broadcasts its battles on the Internet. When Lois investigates, she's kidnapped and forced to participate, and Clark's attempt to save her sparks a surprising turnaround.

Lana is shot after secretly meeting with Lionel at the Daily Planet. As Jimmy studies photos of the scene, he's knocked unconscious and dreams of a 1940s version of Smallville. Meanwhile, Clark discovers why Lana married Lex.

Lex's secret efforts to use DNA from meteor freaks to turn Wes Keenan into a "super soldier" may be exposed by a corrupt senator, so Lex sends Wes to kill him, but Lois sees everything and becomes Wes' next target.

In the sixth-season finale, Clark learns how Lionel got Lana to marry his son; Lana tells Lex that it's over; Martian Manhunter helps Clark stop Lex from finding the last Phantom Zone wraith, hoping to keep him from building his army of super soldiers; and Lois gets into serious trouble when she tries to investigate the secret lab.

Lana absorbs Clark's powers and uses them to go after Lex, first trying to expose his secrets in the Daily Planet, then moving on to a more personal level.

Clark makes a huge mistake when he releases Lara from the crystal, because Zor-El is also released. Elsewhere, the relationship between Lois and Grant heats up.

Chloe runs afoul of the Black Canary when she procures one of Lex's project files for Oliver. Lex suspects the Green Arrow and retaliates, while Lois discovers Oliver's secret.

Lois trails Lex to Detroit, where he has found Kara suffering from amnesia. A busboy obsessed with Kara shoots Lex so he can't take her away, and holds Kara and Lois captive. Chloe finds Lex and offers to heal him, but Clark will not let her.

Clark, through a series of messages sent by Kara from Krypton, discovers what Earth would be like had he never arrived: Jonathan is still alive; Lex is the president; the Luthors have raised Kara; Lana is happily married; and Chloe and Lois are ace reporters.

Clark starts his new job at the Daily Planet, where he is partnered with Lois for a story on a bus explosion. Meanwhile, paramedic Davis Bloome is attracted to Chloe.

Maxima, a queen from planet Almerac, arrives on Earth after being accidentally summoned by Tess. Thinking that her soul mate called her, Maxima sets out to find him, starting with Jimmy, but the men of Metropolis better beware---her kiss is deadly.

A psychotic jeweler kidnaps Jimmy and Chloe after their engagement party and subjects them to a shocking lie-detector test. Posing as a couple while trying to find their friends, Lois and Clark are also forced to answer questions about their feelings for each other.

Clark fears his identity may be revealed after Jimmy snaps a photo of him saving Lois from a mugger. Clark asks Chloe for help to prevent the picture from running on the front page, but to no avail.

The Arctic crystal is anonymously delivered to Clark, and it sends him and Lois to the Phantom Zone, where they run into Kara. She returns Lois to Earth, but inadvertently releases Zod's wife, who takes over Lois' body and wreaks havoc on Metropolis.

Chloe has concerns that Davis will try to stop her wedding. Instead, the ceremony comes under attack by Doomsday, who tries to kidnap the bride. In the melee, Clark and Lois grow closer. Meanwhile, Oliver is off hunting for Lex in Cuba, where he is surprised to find Lana.

Reporter Linda Lake attempts to blackmail Clark for information on the "Red-Blue Blur" in hopes of regaining journalistic fame. Clark chooses instead to reveal his secret identity to Lois and asks her to write the story for the Daily Planet.

Tess tries to manipulate Clark into revealing his powers by staging a midair plane accident as they fly to New York for a press conference. Meanwhile, Davis learns how to control his inner beast.

The magician Zatanna comes to town and grants Chloe's birthday wish to be more like Lois, resulting in the two switching bodies. She also grants Clark his deepest wish.

Pretending she is the superhero Stiletto, Lois secures her star-reporter status by scoring exclusive interviews with the city's newest crimefighter. Clark fears for her safety until she ably saves him from Kryptonite-wielding thugs.

Oliver takes the lead when Clark exhibits resistance to killing Doomsday, and Chloe finds herself caught in the middle of the situation. Meanwhile, a fight between Lois and Tess takes a surprising turn.

Season 9 opens with Clark ready to begin his training with Jor-El, who instructs him to first end things with Lois. Elsewhere, Lois returns to work with no memory of where she's been and meets a new reporter while on assignment; Clark refuses Chloe's request to turn back time to save Jimmy; Zod visits the Luthor home; and Oliver's dark turn continues.

John Corben is mysteriously transformed into a man-machine with superhuman strength after being hit by a truck. He uses his new powers to hunt down the Red-Blue Blur and in the process kidnaps Lois, who is investigating the Blur on her own.

Lois is infected by a zombie plague unleashed on the city by Zod. Its cure lies in the blood of a Kryptonian, and Chloe begs Clark to help, even though he would risk revealing his identity to Zod.

Oliver is kidnapped by a woman named Victoria, aka Roulette, who warns him his life is in danger. Later, Oliver is arrested after Victoria is found dead, prompting him to seek help from Chloe. Meanwhile, Lois is upset with Clark for not telling her about Oliver's attempted suicide.

Oliver is double-crossed by Mia, aka Speedy, a young girl he tries to get off the streets by offering to train her. Meanwhile, Lois turns to Clark for help pursuing an on-air position, and they end up being offered a job as a team.

Lois is kidnapped by Tess and forced to reveal what she learned during the weeks of her disappearance. She witnessed a future with Metropolis controlled by Zod and Clark left without his powers because of the red sun. With this information, Clark makes a big decision about Zod.

Oliver squares off against the Dark Archer, his revenge-minded former mentor, whose nefarious plans endanger Lois, Chloe and Mia.

Clark runs into the magician Zatanna at a comic-book convention, where a magical comic book is stolen by a young man who develops special powers. Calling himself the Warrior Angel, he rescues Chloe from an accident. Meanwhile, Lois grows envious of Clark and Zatanna's connection.

Clark is unwittingly infected with wish-fulfilling Kryptonite on Valentine's Day. When he tells Lois he wishes they had a more conventional relationship, she moves in with him and begins to plan their nuptials. And Clark has a wish for Chloe as well: to better protect him. She responds by targeting Lois.

A once-dead doctor used by the Kandorians for experiments escapes with hostages to prove that aliens exist on Earth. Lois ends up kidnapped by the doctor when she refuses to write about his mission. Meanwhile, Zod discovers the doctor's lab, where he is shot just as Clark arrives.

A romantic getaway turns awkward when Clark and Lois bump into Chloe and Oliver at a bed-and-breakfast. Things grow worse when the Silver Banshee arrives and targets Clark and Oliver. Meanwhile, Tess and Zod have a showdown.

John Corben rescues Lois from an explosion at one of Tess' labs. While investigating the explosion, Clark is infected with red Kryptonite and under its influence takes Zod to the fortress. Later, Chloe agrees to help Tess by sending John to the fortress to keep Clark from exposing the truth.

The Blur's picture is snapped while rescuing Lois from a gun-wielding Raymond Sacks, the former DA she was questioning about his early prison release. While trying to intercept the photo's sale, Lois and Clark run into Checkmate agent Maxwell Lord, who is also hunting down the Blur's identity. Meanwhile, Chloe figures out Zod's secret.

Martha surprises Clark when she returns to town with her boyfriend, Perry White; Chloe and Clark search for the Book of Rao, which may help them stop Zod; and Lois and Perry run into trouble while researching a story on the Red Queen.

In the Season 9 finale, Zod claims to be the Blur and asks Lois to steal the Book of Rao from Clark; Lois asks Clark for full disclosure, but he refuses; Oliver disappears while he and Chloe attempt to fight the Kandorians by reconnecting Watchtower's satellites; Tess is seriously injured after confronting Zod; and Clark and Zod have a showdown as they battle for Earth.

In the Season 10 opener, Lois saves Clark's life by removing the blue kryptonite incapacitating him. Elsewhere, Chloe hunts for Oliver while Tess finds herself in a LuthorCorp lab. And Jonathan returns to the farm with a message for Clark.

Cat Grant is hired by the Daily Planet to replace Lois, who has left for Egypt. When Clark saves Cat from an assassin named Deadshot he uncovers a plot against the Blur. Meanwhile, Lois finds herself under Carter Hall's protection in Egypt.

A powerful dark force threatens Smallville, prompting Jor-El to send Kara, aka Supergirl, to town as backup for Clark. Meanwhile, an anti-hero shock jock becomes possessed by the dark force and takes Lois hostage, and Clark and Kara must save her.

Clark attends his high-school reunion and is visited from the future by Brainiac. He reveals truths about Clark's past, present and future, including the real circumstances surrounding Jonathan's death, Clark's relationship with Lois and his role as a superhero. Meanwhile, Lois is perturbed that no one remembers her short stint as a student.

Lois activates an artifact that turns her into a goddess with superpowers just as she decides to tell Clark she knows his secret. Cat witnesses Lois' new powers and tries to prove that Lois is the Blur. Meanwhile, Clark and Oliver approach Tess for help with Lois.

Upset with Clark's well-intended meddling, Lois insists she can protect herself, but soon ends up in danger when she becomes stranded with a flat tire. Meanwhile, Tess looks for ways to help Alexander, who is aging very quickly.

Lois' sister and dad visit unexpectedly for Thanksgiving. Tensions rise when the General bad-mouths superheroes and informs Clark of his efforts to pass the vigilante registration act. Meanwhile, Rick Flagg plots to kill the General.

Lois views a video her mom made for her before her death. The tape prompts Lois to make a major decision about Clark, which leads to her encountering Jor-El and Lara at the Fortress. Meanwhile, Tess has a nightmare about a music box that she later finds at the mansion. Her and Clark's investigation takes them to an orphanage.

The truth behind the Vigilante Registration Act is revealed when Oliver is jailed and subjected to harsh testing by Col. Slade after he volunteers to participate. Clark is joined by Aquaman and his wife, Mera, in his efforts to rescue Oliver. And Lois is miffed when Clark won't let her help, so she sets out on her own.

Anti-superhero citizens attack the Green Arrow as he tries to stop a mugging, and Clark learns the attackers all have a darkness tattoo. Elsewhere, Carter Hall and Star Girl help Clark pursue Slade, who has kidnapped Lois.

The VRA releases Clark, Oliver, Lois and Dinah, who all have flashbacks of Chloe's involvement in their capture. Trust becomes an issue when Chloe returns to town and Dinah fears she is now a traitor.

Clark sees his mom get shot while watching her speak at a pro-vigilante rally on TV. To raise his spirits Lois and Chloe share videos in support of the Blur with Clark. Elsewhere, Lionel Luther comes forth and reclaims his company from Oliver and Tess.

Oliver and Chloe are kidnapped while investigating a rash of murders carried out by Desaad, who then attempts to sicken Chloe with the darkness. Meanwhile, Lois advises Clark to get a disguise to protect his identity.

Everyone loses their memory after drinking spiked champagne, courtesy of Zatanna, at Clark and Lois' bachelor and bachelorette parties. While hunting for her missing engagement ring with Oliver, Lois is accused of theft by Fortune, the casino owner. Elsewhere, Clark recalls stealing an armored truck.

Clark and Lois receive a stunning gift from Tess. Meanwhile, Tess and Lionel struggle for control of the Luthor name.

Lois turns to Emil for help after Clark Luthor sends Clark back to the alternate reality, where he encounters an irate Jonathan Kent. Meanwhile, Clark Luthor tells Tess he'll kill her if she doesn't take his side.

Lois advises Clark on how to distinguish himself from the Blur, but when a fame-seeking superhero from the future begins stealing the limelight Lois goes on a mission to spotlight the Blur. Meanwhile, a boy becomes fused to an alien weapon and attacks Metropolis.

Oliver tricks Clark into taking him to the Phantom Zone to investigate its escape portal. Once there they discover that Zod has taken over as leader. Meanwhile, Lois is upset to learn that Clark has trusted Tess with a secret.

Lois walks in Clark's shoes for a day when Jor-el bestows Clark's superpowers on her as a wedding gift. But when the Toyman returns to Metropolis it's Lois who must stop him. Meanwhile, Oliver bumps into Kara while searching for the Bow of Orion.

In Part 1 of the two-part series finale, Clark tries to persuade runaway bride Lois to still marry him. Meanwhile, Lionel kidnaps Tess, and darkness envelops Oliver.