<P> Introduced in the series pilot, Chloe spends much of season one helping her best friend Clark Kent (Tom Welling) stop the citizens of Smallville who have developed special abilities from genetic mutations, caused by the meteor rocks that fell to Smallville in 1989, from committing crimes . It is established that Chloe is the editor of the school newspaper the Torch at the start of the first season . Her journalistic curiosity--always wanting to "expose falsehoods" and "know the truth"--causes tension with her friends, especially when she is digging into Clark's past in the season two episode "Lineage". In the early seasons, Chloe hides the fact that she is in love with Clark, although the feeling is not reciprocated; she confesses her true feelings to Clark in season two's "Fever" while he is sick, but he calls out Lana Lang's name in his delirium . Her feelings for Clark get in the way of her better judgment as she betrays his trust in the season two finale, after witnessing him and Lana Lang (Kristin Kreuk) sharing a kiss in his barn, and agrees to uncover information on Clark for Lionel Luthor (John Glover) in exchange for a job at the Daily Planet . </P> <P> Chloe and Clark patch their relationship in the season three episode "Whisper", after Clark discovers that she has been helping Lionel . When Chloe stops her investigation, Lionel has her fired from the Daily Planet, and also fires her father from his job at LuthorCorp . In season three's "Forsaken", Chloe decides to assist Lex Luthor (Michael Rosenbaum), Lionel's son, with getting Lionel arrested for the murder of Lex' grandparents; Chloe's hope is to get out from under Lionel's control . In the season three finale, the F.B.I. place Chloe and her father in a safe - house until Lionel's trial; unfortunately, the safe - house explodes once Chloe and her father enter and they are presumed dead . Chloe's cousin, Lois Lane (Erica Durance), comes to Smallville to investigate Chloe's death in the fourth season premiere . In season four's "Gone", Clark and Lois team - up and discover that Lex's security team found the explosives in the safe - house, pulled Chloe and her father to safety before they detonated, and that he has been hiding her ever since . After Chloe's testimony in the same episode, Lionel is convicted of murder and sentenced to life imprisonment . In the season four episode "Pariah", Chloe discovers Clark's secret when Alicia Baker (Sarah Carter), Clark's girlfriend, decides that it needs to be exposed to the world in order for him to feel more comfortable about who he really is . Alicia hopes that Chloe will write a story exposing Clark, but Chloe decides that Clark kept his secret for a reason and decides not to write the story . </P> <P> Chloe finally reveals to Clark in the season five premiere that she has known his secret, but that she wanted him to be comfortable enough to tell her on his own . At the same time, Clark reveals that he was not infected by the meteor rocks in Smallville, as Chloe initially suspected, but that he is in fact an alien who was sent to Earth as a baby during the meteor shower of 1989 . In season five's "Thirst", Chloe earns her dream job at the Daily Planet, starting in the basement . In the season six episode "Justice", Chloe begins assisting Green Arrow (Justin Hartley) and his team of superheroes under the codename "Watchtower". In "Freak", she discovers she herself is meteor - infected, with an unknown ability, and begins to worry that she is a "time bomb" heading towards insanity . She later discovers in "Progeny" that her institutionalized mother, Moira Sullivan (Lynda Carter), is meteor - infected as well . In the season finale, Chloe learns that her special power lets her heal any wound and even reverse death, when it activates to save Lois . In season seven's "Descent", when Chloe attempts to keep information regarding "The Traveler" a secret from Lex, who is unaware that "The Traveler" is really Clark, he fires her from her job at the Daily Planet . When in "Sleeper", Lana falls into a catatonic state having been attacked by the Kryptonian artificial intelligence known as Brainiac (James Marsters), Chloe takes over Lana's Isis Foundation, a free clinic for individuals who have been infected by the meteor rocks . In the seventh season finale, Chloe is attacked by Brainiac, but her healing powers prevent him from harming her . When she returns home, Jimmy Olsen (Aaron Ashmore), her on - again - off - again boyfriend since season six, proposes marriage . Before Chloe can answer the Department of Domestic Security (DDS) appears and arrests her for hacking into the government database . </P> <P> At the start of season eight, it is revealed that Chloe was not arrested by DDS, but Lex's security personnel impersonating DDS agents . While subjected to their tests, Chloe discovers that her altercation with Brainiac has apparently caused to her to lose her meteor - related powers, but instilled two new abilities: vast super intelligence and technopathy . Returning to Smallville, Chloe reopens the Isis Foundation . Though she loves Jimmy, she finds herself attracted to paramedic Davis Bloome (Samuel Witwer). In the episode "Abyss", Brainiac's infestation causes Chloe to lose her memories . Clark takes Chloe to his biological father Jor - El, who restores her memories . After Chloe marries Jimmy in "Bride", she is kidnapped by Doomsday, a genetically engineered killing machine bent on destroying Earth and becomes Brainiac's vessel once again . Brainiac attempts to drain the world of all its human knowledge but is stopped and removed from Chloe's body by the Legion, superheroes from the future, in "Legion". In "Hex", Chloe assumes the codename Watchtower full time because she feels her life needs more meaning . Chloe discovers that Davis is Doomsday in "Eternal". She attempts to assist Davis' suicide using kryptonite; when this fails, she stays by his side in order to keep Doomsday under control . In the episode "Beast", she and Davis leave town together; Chloe reasons it will protect Clark . In the season eight finale, she uses black kryptonite to separate Davis from Doomsday; Clark buries Doomsday beneath Metropolis . However, when Davis discovers that Chloe is still in love with Jimmy, he stabs Jimmy and attempts to kill Chloe; Jimmy impales him on a metal rod, and they both die . Chloe vows to keep the Watchtower Jimmy gave her as a wedding gift open, in the hope that all lost heroes--namely Oliver and his team--will find their way home . </P>

When does clark reveal his secret to chloe