Question: By what means did Sitterson discover that Marty is still living?
About the article "The Cabin in the Woods", section "Plot".

Candidate passages:
Working from a hidden underground facility, senior technicians Gary Sitterson and Steve Hadley initiate plans for a mysterious ritual – reportedly one of several others taking place around the world.
Also present is specialist Wendy Lin, who discloses that a similar operation undertaken by their Swedish counterparts has just ended in failure.
Meanwhile, American college students Dana Polk, Holden McCrea, Marty Mikalski, Jules Louden, and Curt Vaughan are spending their weekend at a seemingly deserted cabin in the forest.
It soon becomes clear that Sitterson and Hadley are manipulating this setting from afar, even intoxicating the teenagers with psychotropic drugs that gradually hinder rational thinking while increasing libido.
After the door to the cabin's darkened cellar swings open on its own during a tipsy game of "Truth or Dare", for example, both technicians coerce their charges into investigating the contents within.
The group soon uncovers a plentiful assortment of bizarre articles, including an old diary once maintained by Patience Buckner, onetime cabin resident abused by her sadistic family.
Dana, who takes an interest in Patience, subsequently recites incantations from the journal and inadvertently summons the zombified Buckner clan.
Leaving Dana, Holden, and Marty behind with the book, Curt and Jules retire outside – where Hadley successfully induces them to have sex.
Set upon by marauding Buckners, Jules is decapitated but Curt escapes, sounding the alarm.
Marty, a frequent marijuana smoker, becomes justifiably paranoid, declaring that unseen figureheads have been toying with their crisis.
Locating concealed surveillance equipment, he theorizes that the predicament may be a gimmick for reality television before being dragged off to be killed by Judah Buckner.
Terrified, Curt, Holden, and Dana attempt escape in their RV, though Sitterson triggers a tunnel collapse, rendering the highway impassable.
Curt jumps a ravine on his motorcycle in a desperate bid to reach an adjoining road, but is killed crashing into a camouflaged force shield - apparently erected by the technicians.
His demise convinces Dana that Marty's concerns may have been founded.
Veering off the tarmac, the RV plummets into a nearby lake after Father Buckner surfaces inside and stabs Holden.
Dana survives the impact, but is confronted by Matthew Buckner when she swims ashore.
As he delivers his final blow, the Facility staff celebrate the completion of their ritual.
Sitterson receives a phone call informing him that Marty is still alive.
Rescuing Dana, Marty reveals that he was able to overpower his assailant upon being taken into an obscured elevator.
They infiltrate the Facility, where a menagerie of monsters are imprisoned.
Dana observes a cenobite-like creature clutching a globe she observed in the cabin's cellar, indicating that the items there dictate which monster will be unleashed on its concurrent occupants.
She and Marty are cornered by a private security team, but before they can be captured, manage to release the monsters, which run rampant throughout and slaughter the Facility's staff, including Hadley.
Sitterson escapes, only to be inadvertently stabbed by Dana in the lower levels of the building.
Upon entering an underground temple, the two survivors meet the project Director who explains that every year worldwide rituals commence to appease malevolent beings identified only as "Ancient Ones" living beneath the Facility, they are kept in perpetual slumber through an annual pars pro toto sacrifice of five young people embodying certain archetypes: the Whore (Jules), the Athlete (Curt), the Scholar (Holden), the Fool (Marty), and the Virgin (Dana).
The order in which intended victims perish is flexible, as long as the Whore is first and the Virgin is last (or optionally survives, so long as the others die).
The Director urges Dana to shoot Marty, completing the ritual, but they are interrupted by a werewolf which Marty fends off after it attacked Dana.
Patience Buckner arrives, killing the Director, and Marty pushes them into a chasm.
Dana and Marty accept that it might be better for another species to take humanity's place if this is the price of its continued existence.
They share a final joint as an Ancient One finally stirs, destroying the Facility.
Years later, Marty briefly reappears in early 2004 to testify on Todd's behalf when he is on trial for supposedly raping Blair; she explains that she is now openly living in California as a practicing psychiatrist working with sex offenders, and tells the court that she believes Todd is a "changed man".
Despite never forgiving Todd for her rape, Marty believes that Todd is so traumatized, that he will never commit the crime of rape again.
She urges Blair, who is unaware that she is suffering from a brain tumor, to reconsider her recollection of the night Todd "raped" her.
Marty makes no mention of Patrick or their child, or how they have eluded the terrorists hunting the Thornharts.
The following year, Marty appears again, as a hallucination of Todd's, taunting him after his rape and torture at the hands of Margaret Cochran.
This spectre comments on the irony of "Margaret Todd", due to Marty's birth name also being Margaret.
Marty returns to Llanview on November 17, 2006 (now played by Christina Chambers).
Marty is shocked to learn that her son, high school quarterback Cole (her child by Patrick), is being accused of attacking Todd and Blair's daughter, Starr.
Marty reveals that she has just recently moved back to Llanview and has set up her practice, and that she and Cole are still reeling from Patrick's mysterious death.
Todd, Blair, and Marty are all determined to keep their children apart.
Marty serves as psychiatric consult in the court case against the nefarious Dr. Spencer Truman, declaring him mentally unfit and thus sparing him a prison sentence, outraging Todd, Blair, and Llanview Chief of Detectives John McBain, whose father was killed by Spencer in Atlantic City.
Later, when Spencer is killed while attempting to abduct and rape a hospitalized Blair, McBain is determined to find the culprit.
Marty, meanwhile, begins having disturbing visions of being in Blair's hospital room on the night of the murder, and seeing a scalpel.
Marty confesses her fears of having killed Spencer to her therapist, but can not fully remember what her mind has blocked out from that fateful night.
When the lovestruck Miles Laurence is determined to win Marty's heart, he takes extreme measures, stealing Marty's audiotaped "confession" from her therapist's office and blackmailing her with it, forcing Marty to marry him in order to retain custody of her son.
Marty finally tells John McBain about her precarious situation, and John becomes determined to exonerate Marty, find Spencer's true murderer, and end Miles' sick game with Marty's life.
Before John can learn the truth, however, the evidence against Marty becomes overwhelming, and she is arrested as the prime suspect in Truman's murder.
John and Marty struggle to uncover the hazy details surrounding the night Spencer was killed, and eventually Marty remembers that she was never able to strike Spencer; instead, he assaulted her and left her in a vacant hospital room, leaving her with a head injury.
Soon thereafter, John deduces that Lindsay Rappaport is the real murderer, and Marty is released from prison.
After being exonerated, Marty is determined to move forward with her life and end her marriage to Miles.
A guilt-ridden Miles, having seen the error of his ways, helps the process along by confessing in open court to having blackmailed Marty into their marriage.
Weeks later, Marty's marriage is annulled.
Cole and Jessica Buchanan urge Marty to consider a romantic future with John McBain, but a bashful and unsure Marty refuses to consider it.
Regardless, Marty seeks John out, and the two spend an afternoon walking the Llanview docks.
At the close of the evening, Marty impulsively kisses John.
Marty instantly apologizes, but an intrigued John tells her not to be sorry.
They share a romantic kiss again soon after.
John and Marty continue to bond during the custody trial for Tommy McBain, but after Marcie McBain goes on the run with her adoptive son, John leaves Llanview to pursue his sister-in-law, along with Todd Manning.
After John starts a barfight in Decatur, Georgia, he and Todd are arrested.
Marty and Blair go down to Decatur and bail them out.
Marty and Blair insist on joining John and Todd as they search for Marcie in the hopes of preventing the two enemies from killing each other.
After the group hits the road, John's car breaks down, and the quartet is forced to get a room at a local motel.
Initially there is only one room available but Todd uses his "charm" and money to obtain a room from one of the other guests.
Marty and John spend the night together in the first room.
During the evening, John opens up to Marty about the murder of his former fiancee, Caitlin Fitzgerald, and explains that Lee Ramsey, the FBI agent pursuing Marcie, holds a grudge against him because of Caitlin's death.
Marty in turn confides in John about Patrick's murder.
She reveals that Patrick was killed by old enemies from Ireland, and that his old friend Simon Ryerson came to her door to give her the news.
Having bonded by unburdening themselves, John and Marty end up making love.
After Cole is abducted back in Llanview by a mysterious man in a "Death" costume, another unseen figure shows up at John and Marty's motel room and grabs her just as she gets a call from Starr on Cole's cell phone.
Marty and Cole are taken to Ireland and held hostage by none other than Patrick's "old friend" Simon, who was actually the terrorist who killed Patrick.
Simon is determined to get an incriminating "list of names" which Patrick kept from his days with the "Men of 21", but is frustrated to discover that Marty has no knowledge of the list; in reality, Patrick hid the list on a microchip inside one of his own poetry books.
John finds the chip, and he and Lee Ramsey pursue Marty and Cole overseas and make contact with Simon in Ireland.
They set a time and meeting for an exchange: Marty and Cole for Patrick's microchip.
Things seem to be going as planned, until Ramsey fires upon the van which contains Marty and Cole in an attempt to apprehend the terrorists.
The van spins out of control and goes careening over a cliff.
Racing to the bottom of the rock quarry, John struggles to free Marty from the wrecked van, but she insists that he find Cole first, saying she has no life without her son.
John reluctantly leaves her side and is able to rescue Cole, who was thrown from the van in the crash, but watches helplessly as the van explodes.
Marty is presumed dead, and the bereaved John and Cole return to Llanview.
In the aftermath of Marty's death, her loved (and not-so-loved) ones deal with her loss in their own way: John discovers her posthumous Christmas gift, a dartboard with Todd's face on it; Cole undertakes grief counseling with friend Langston Wilde; and Todd quietly orders a lavish flower arrangement for her memorial service, without leaving his name. 
Killings take place in early 2009, with letters left on the bodies that spell out KAD, Todd's old fraternity, where he, Powell Lord III (Sean Moynihan), and Zach Rosen raped Marty, when they were in college.
Blair is the first to be attacked and not die, and Todd is a possible suspect in the case.
Blair fears she will lose her children, so her lawyer Téa suggests she marry John, which surprises them both.
After some talking John proposes to Blair and she accepts.
She is also granted custody of their children.
In August, they plan to get an annulment, but he has the papers changed to say divorce, because he wants it on record that his first marriage was Blair although the marriage was never consummated.
John began a relationship with Marty after his divorce from Blair.
Marty is grateful when John saves Cole, Hope and Starr from drug dealers.
John and Marty make love and begin a relationship.
In the fall of 2009 John reconnects with Natalie as he investigates Jessica's stalking and Jared Banks' (John Brotherton) beating.
John is immediately suspicious of Jared and admits to Marty that he does not like Jared simply because he is Natalie's husband.
When Jared accusing him of still being in love with Natalie, John answers yes, and admits he will always care for her.
Marty senses the effect John and Natalie have on each other, but John tells her, he and Natalie were a long time ago.
The investigation reveals that Mitch Laurence (Roscoe Born) is behind the stalking and that Jared was blackmailed into helping, in order to protect his father Charlie Banks.
When Jared is killed by Mitch, Natalie is devastated.
John supports Natalie through her grief.
When she stabs Mitch with a letter opener, John transfers the blood off the letter opener Natalie used unto his own letter opener leaving his fingerprints.
John then hides the letter opener covered in Mitch's blood and his fingerprints in his drawer, and tells investigators that Mitch stabbed himself.
When Mitch is interviewed, he tells Brody, that John stabbed him.
When Dorian, under the instruction of Mitch, brings forth John's hidden letter opener, John is charged with the crime.
Natalie tries to confess, John continues to state he stabbed Mitch, and tells Bo Natalie is trying to protect him.
Marty questions John as to why he would risk everything for Natalie, and why he didn't consult her, his girlfriend, before framing himself.
When John is arrested, Natalie tells her family John is covering for her and confesses to Bo.
However, Marty arranges for Marty, Jessica, and Cole to come forward and admit to stabbing Mitch, the LPD having these new suspects coming forward forces John's release.
Mitch gets Dorian hire Mayor Lowell, and he officially charges and arrests John for the attempted murder of Mitch.
In February, Natalie and Brody break John out of jail so that they can rescue Jessica who has been kidnapped by Mitch.
As Natalie is driving, the car steers off the road as Natalie tries to avoid colliding with another car.
Natalie is trapped and John gets her out before the car explodes.
John finds a deserted cabin, where he takes Natalie.
Natalie, suffering from a head injury, believes John to be Jared.
John kisses the hallucinating Natalie and admits he loves with her.
When Natalie realises her hallucinations are not real, John and Natalie admit they still have feelings for each other and kiss again as Marty enters the room.
Although John tells Marty he wants to make it work with her, it is clear that John has feelings for Natalie.
John visits Natalie at Llanfair and the two end up kissing again.
Before John is able to tell Marty about his feelings for Natalie, he learns that Marty is pregnant with his child from Natalie, who congratulates him, not realizing he did not know.
After she leaves, Marty arrives and he questions her about it.
They discuss it and he reassures her that while he has no idea what he's doing, he wants to have the baby, and she's very happy and relieved.
On St. Patrick's Day, John and Natalie stare at one another as he dances with Marty.
After being pushed down the stairs, Marty and John discover that their baby has been miscarried.
John and Natalie get back together, but she does not mention to him that she had a one night stand with Brody Lovett (Mark Lawson).
Soon after, Natalie tells John she is pregnant and does not tell him about the possibility of Brody being the father.
In December 2010, John asks Natalie to marry him because he loves her and wants her to be his wife.
Despite her happiness, Natalie is hesitant due to Marty knowing the secret of her child's paternity but ultimately she lets herself accept.
John wants to get married as soon as possible, and suggest they get married on New Year's Eve.
John selects Brody as the best man, and Natalie choses Jessica as her maid of honor.
The couple say their vows and exchange rings but are never pronounced man and wife as the wedding is interrupted by Marty. 
Joseph Carlyle "Lyle" Sitterson (January 17, 1911 – May 19, 1995) was an American educator who served as chancellor of the University of North Carolina at Chapel Hill from February 16, 1966, to January 31, 1972.
A native of Kinston, North Carolina, Sitterson first came to UNC in 1927 as an undergraduate student.
He remained at the University, joining the faculty of the history department in 1935 and later earning his Ph.D., also in history.
In 1955, Sitterson became the dean of the School of Arts and Sciences, becoming vice chancellor in 1965 under Chancellor Paul F. Sharp.
On February 16, 1966, Sitterson was installed as chancellor of the University, succeeding outgoing Chancellor Paul Sharp.
Sitterson took office in the midst of the controversy surrounding the North Carolina Speaker Ban Law, a state law passed on June 26, 1963 by the North Carolina General Assembly which forbade individuals who were known to be members of the Communist Party or had invoked the Fifth Amendment in connection with congressional investigations of communist activities from speaking on any of the campuses of the University of North Carolina.
Student leaders and faculty members of the University of North Carolina at Chapel Hill led a campus movement in opposition to the law which climaxed with the invitation of speakers Herbert Aptheker (an avowed communist) and Frank Wilkinson (an outspoken critic of the House Un-American Activities Committee).
Two weeks into his chancellorship, Sitterson denied the students' request to allow Aptheker and Wilkinson to speak on campus.
On March 2, 1966, Frank Wilkinson spoke to a crowd of more than 2,000 students from across a wall that separated the campus of the University from the surrounding town of Chapel Hill - thereby avoiding trespass of the law.
On March 9, 1966, Aptheker followed in Wilkinson's footsteps, speaking to a similar sized crowd from a position across the wall.
The denial of the speakers' invitations was used as the basis for the lawsuit which, in 1968, eventually overturned the North Carolina Speaker Ban Law before a U.S. District Court in Greensboro, North Carolina.
Student leaders took the role as the plaintiffs in the lawsuit while Sitterson, UNC System President William C. Friday; (somewhat ironically as Sitterson and Friday were firm opponents of the Speaker Ban), the University of North Carolina and even the State of North Carolina were the defendants.
Sitterson faced other challenges during his tenure including a 1969 strike of campus dining facility employees which was led by a new African American student organization called the Black Student Movement and a general walkout of students following the murders of four Kent State University students in May 1970.
Throughout Sitterson's career as an administrator at the University of North Carolina at Chapel Hill, he continued to teach courses in history.
Chancellor J. Carlyle Sitterson was succeeded by Chancellor Ferebee Taylor on January 31, 1972.
Sitterson also worked with a number of service organizations, specifically Research Triangle Institute and the North Carolina Center for the Advancement of Teaching (NCCAT), a group formed in 1984 with the goal of promoting professional development among teachers in the arts, sciences, and humanities.
Sitterson served as NCCAT's first board chair.
In 1987, the University opened Sitterson Hall, named for the former chancellor, which is currently the home of the UNC Department of Computer Science. 
Marty, portrayed by Wayne Wilcox, was briefly introduced in the season four episode "The Hobbit, the Sofa and Digger Stiles" as a student at Yale who "had an unfortunate experience with a keg and a party and a need to take clothes off and fall asleep in a hallway."
After Rory tells this story to her mother he is nicknamed "naked guy".
He is also adopted.
Shortly after, in "The Fundamental Things Apply", Marty reappeared, fully clothed.
He invited a late and dishevelled Rory to eat breakfast with him and a group of his friends, who had adopted the name 'The Breakfast Crew' because it 'wasn't an official club or anything'.
Marty appeared once more in that season, albeit briefly.
He made several appearances in season five, including an appearance that seemed to be his last.
During this, he went to dinner with Rory Gilmore, Logan Huntzberger and a group of Logan's well-to-do friends, some of whom had treated Marty with a lack of respect in the past asking him 'how he could be so big but yet so very small'.
Marty had a horrible time and ended up not being able to afford his split of the bill and begrudgingly accepted Rory's offer to pay for it, promising to pay her back.
On return to Rory's dorm, Marty revealed what many had already known, that he had romantic feelings for Rory.
Rory rebuffed him, informing him of another fact many (including Marty, to a degree) were already aware of: she liked Logan.
Marty was not seen for nearly two years, until the November 14, 2006 episode, "French Twist".
He was shown briefly, near the end of the episode, and was revealed to be in a relationship with Rory's new friend, Lucy (Krysten Ritter).
In a move that confused Rory, Marty pretended that he and Rory did not know one another when Lucy introduced the two.
When Rory asks him why he relays that he feels it would be weird if Lucy knew they were once friends.
Though Rory is still confused, she does not tell Lucy she knows Marty.
In "Knit, People, Knit!
", Marty bartends Lucy's birthday party, which Rory attends.
Rory took initiative and they smoothed things over, but the newfound peace was quickly ruined as Marty made it obvious that he still had feelings for Rory.
In the next episode, "Merry Fisticuffs", Logan, Rory, Marty and Lucy were enjoying dinner together when Lucy inquired as to how Rory and Logan met.
Logan answered, honestly, that Marty introduced them because he knew that he still had feelings for Rory.
Logan later admitted that he was a bit jealous.
Lucy was upset after realizing that both Marty and Rory had been lying.
She and Marty end up breaking up.
She and Rory become friends again after Rory writes an apology letter to her, and Lucy ultimately realizes the situation wasn't Rory's fault.