For fan theories about these unanswered questions, see: Charlie Pace/Theories

• What caused Charlie to act so strangely when he wanted to baptize Aaron? ("Fire + Water")
• Why does Charlie appear to Hurley after he has died? ("The Beginning of the End")

For fan theories about these unanswered questions, see: Cindy Chandler/Theories

• Does Cindy know that her lover Gary Troup was on the plane? Does she know that he is dead? ("Pilot, Part 1")
• If Cindy was with Charlie when the plane crashed, how did she end up with the Tailies? ("Pilot, Part 2") ("The Other 48 Days")
• Why was Cindy taken by the Others so much later than the other Tailies? Was Cindy on the list? If so, why wasn't she taken sooner? If not, what changed? ("Abandoned")
• How and why has Cindy been "converted" by the Others? ("Stranger in a Strange Land")

For fan theories about these unanswered questions, see: Claire Littleton/Theories

• Was the seagull message ever received? ("Par Avion")
• Why did she abandon Aaron? ("Cabin Fever")
• Why is she behaving so strangely with Christian? ("Cabin Fever")
• Why did Christian bring Claire to Jacob's cabin?
• What was the meaning of the dream Claire details in her diary about the "Black Rock" in the Episode ("Special") from Season One?
• Where is Claire now, and will she ever be found?

For fan theories about these unanswered questions, see: Hugo "Hurley" Reyes/Theories

• Where did the nickname "Hurley" come from?
• Did Hurley cause the collapsing deck accident, or would it have happened anyway? ("Dave")
• What caused the bad luck surrounding Hurley and Sam Toomey? Is there really a curse? ("Numbers")

For fan theories about these unanswered questions, see: Jack Shephard/Theories

• Why was Jack so far from the crash site when he woke up, in a bamboo forest which is impossible to just fall through in? ("Pilot, Part 1")
• Why did Jack want Achara's tattoo so badly, and why was he attacked for it? Why is Achara's tattoo in Chinese rather than Thai? ("Stranger in a Strange Land")

For fan theories about these unanswered questions, see: Jin-Soo Kwon/Theories, Sun-Hwa Kwon/Theories

For fan theories about these unanswered questions, see: Kate Austen/Theories

• How did Kate get the other key to the safety deposit box? ("Whatever the Case May Be")
• Why has Kate seen the same black horse on various occasions? ("What Kate Did")

For fan theories about these unanswered questions, see: Libby Smith/Theories

• Why was Libby in the Santa Rosa Mental Health Institute? ("Dave")
• Did Libby remember Hurley from the hospital?
• Why was Libby in Australia, and why was she leaving? ("?")

For fan theories about these unanswered questions, see: John Locke/Theories, Anthony Cooper/Theories

• How did Locke acquire his knife throwing and tracking skills? ("Walkabout")
• What happened when the commune collapsed? ("Further Instructions")
• How and why was Locke cured of his paralysis? ("Every Man for Himself")
• Why did the Monster not attack Locke at first, then later drag him into a hole? ("Walkabout") ("Exodus, Part 1")
• Why do Locke's legs sometimes fail him, such as when he and Boone were on their way to find the Beechcraft? ("Deus Ex Machina")
• How did Locke escape the Swan when it imploded? ("Live Together, Die Alone") ("Further Instructions")
• What made Locke mute immediately after the implosion? ("Further Instructions")
• Was Ben really coming to the camp to recruit Locke? ("Three Minutes")
• Is Locke on the "list"?
• Why does Locke have a special connection to the Island?
• What is the connection between Locke and Jacob's nemesis?

For fan theories about these unanswered questions, see: Eko Tunde/Theories, Yemi Tunde/Theories

• Why was Eko dragged into the jungle by the Others? ("The Other 48 Days")
• How did Eko survive the implosion of the Swan? ("Further Instructions")
• Why did the "monster" kill Eko?

For fan theories about these unanswered questions, see: Rose Nadler/Theories

• Why did Rose seem to know that Bernard was alive? Was she in denial, or did she somehow know? ("Walkabout")

For fan theories about these unanswered questions, see: James "Sawyer" Ford/Theories

For fan theories about these unanswered questions, see: Sayid Jarrah/Theories

• How did Nadia end up in the US? ("The Greater Good")
• What happened to Sayid during the seven years he traveled around, searching for Nadia?
• If the government officials told Sayid that Nadia was alive before he boarded Flight 815, why did he then tell Danielle Rousseau that Nadia was dead? ("Solitary") ("Live Together, Die Alone")
• What is the "Basra Incident" referred to by Juliet? ("One of Us")
• What is Sayid digging a hole for? ("The Brig")

For fan theories about these unanswered questions, see: Walt Lloyd/Theories, Michael Dawson/Theories, Vincent/Theories

• Does Walt have "special powers"? If so, how and why? ("Special") ("Man of Science, Man of Faith") ("Abandoned")
• Why did Walt tell Locke not to open the Hatch? How did he know anything about it? ("Born to Run")
• What did Walt see that frightened him enough to want to leave the Island? ("Born to Run")
• Why did the Others want Walt? ("Exodus, Part 2")
• Why does Shannon hear Walt say (backwards) not to push the button? ("Abandoned")
• Why do Shannon, Sayid, and Locke see Walt in places he shouldn't be?
• Why did the Others make Walt take "tests"? What were the tests for? ("Three Minutes")

For fan theories about these unanswered questions, see: Charlotte Lewis/Theories

• Why did Matthew Abaddon send a cultural anthropologist on the mission to find the Island?

For fan theories about these unanswered questions, see: Daniel Faraday/Theories

For fan theories about these unanswered questions, see: Miles Straume/Theories

• What does he mean by "I'll take care of Charlotte"?
• How did he know "Kevin" wasn't Michael's real name? ("Meet Kevin Johnson")

For fan theories about these unanswered questions, see: The Others/Theories

• How many Others are there?
• Why do the Others want the survivors to stay away from parts of the Island?
• Why did the Others kidnap members of the Tailies and various children? ("The Other 48 Days") ("Par Avion")
• Why do they believe they are "the good guys"?
• Why do the Others take blood samples from the people in their custody? ("Three Minutes") ("A Tale of Two Cities")

For fan theories about these unanswered questions, see: Alex/Theories

For fan theories about these unanswered questions, see: Beatrice Klugh/Theories

• What is Bea's role and rank within the Others?

("Three Minutes")

For fan theories about these unanswered questions, see: Benjamin Linus/Theories

• Why did Ben see his mother twice? ("The Man Behind the Curtain")
• How did Ben become the leader of the Others? ("The Man Behind the Curtain")
• Why does Ben seem relatively calm when Oceanic 815 crashes, and the discharge occurs? ("Live Together, Die Alone") ("A Tale of Two Cities")
• Why does Ben seem to expect a plane to crash on the Island, seconds before Oceanic 815 crashes? ("A Tale of Two Cities")
• If Ben wanted to capture Jack, Kate, and Sawyer, why did Tom not do so during their first encounter? ("The Hunting Party") ("Exposé")
• Did Ben kill or order the death of the real Henry Gale? ("Dave")
• How did Ben get caught in one of Danielle's traps? What was he doing alone in the jungle? If he wanted to infiltrate the Losties' camp, why didn't he send someone else?
• Why didn't Ben escape the Losties when he had the chance, during the lock down? ("Lockdown")
• Why did Ben tell Locke that nothing would happen if he did not push the button? ("Dave")

For fan theories about these unanswered questions, see: Ethan Rom/Theories

• What was Ethan's rank in the Others' hierarchy?
• How did Ethan acquire such enormous strength when fighting Jack? ("All the Best Cowboys Have Daddy Issues")
• How does Ethan get the scratches on his face after Claire's escape? ("Homecoming")
• Why did Ethan kidnap Claire on his own, against the Others' plans? ("Maternity Leave")
• Did Ben condone or approve of Ethan killing and attempting to kill Losties? ("All the Best Cowboys Have Daddy Issues")
• If Ethan really was the Others' surgeon, why did Ben send him on such a dangerous mission to the survivors? ("A Tale of Two Cities")
• Who was Ethan's wife? (Mx10)

For fan theories about these unanswered questions, see: Isabel/Theories

• How and when did Isabel join the Others?
• What is Isabel's rank in the Others' hierarchy? How is she their "sheriff"? ("Stranger in a Strange Land")
• What is Isabel's role in the Others' trial and sentencing system? How does that system work? ("Stranger in a Strange Land")

For fan theories about these unanswered questions, see: Jacob/Theories

• What is the ash-like substance around Jacob's cabin? ("The Man Behind the Curtain")
• What is the significance of the dog painting and the jars of liquid in Jacob's cabin? ("The Man Behind the Curtain")
• Why did Jacob make a list? If Jack wasn't on it, who was? ("I Do")
• Why do the Others have such faith in him as their leader when they have not even seen him? How do they know that he is a "great man" or a "magnificent man", just from Ben's reports? ("The Man Behind the Curtain")
• Was it Jacob who said "Help me" to Locke, and why did he say it? Why didn't Ben hear it? ("The Man Behind the Curtain")
• How did the cabin's inhabitant move objects? How did the lantern fire go out? ("The Man Behind the Curtain")
• What is the circular pattern on the chair? ("The Man Behind the Curtain")
• Why does Jacob's cabin appear to Hurley, and seem to shift around? ("The Beginning of the End") ("The Economist")

For fan theories about these unanswered questions, see: Richard Alpert/Theories

• Why does Richard appear not to be aging?
• How and when did Richard arrive on the Island?

For fan theories about these unanswered questions, see: Juliet Burke/Theories

• What does Juliet's mark mean? ("Stranger in a Strange Land")
• How did Juliet learn to fight? ("Left Behind")
• How did Juliet dislocate her shoulder 4 times? ("Left Behind")
• Does Juliet know more about the Monster than she says? ("Left Behind")

For fan theories about these unanswered questions, see: Mikhail Bakunin/Theories

• Was Mikhail recruited by the Others before or after the Purge? ("Through the Looking Glass")
• What happened to Mikhail's eye? ("Enter 77")
• Does the glass eye found at the Arrow belong to Mikhail? ("The Other 48 Days")
• What is Mikhail's document about? ("Enter 77")

For fan theories about these unanswered questions, see: Tom (Other)/Theories

• How and when did Tom join the Others?
• What was Tom's rank and role among the Others?

For fan theories about these unanswered questions, see: Aaron Littleton/Theories, Claire Littleton/Theories, Richard Malkin/Theories

• Was Richard Malkin telling Mr. Eko the truth about being a fraud? If so, why did he refuse to take Claire's money, and even give her $6000 and a free airline ticket? ("Raised by Another")("?")
• Why did the Others want Aaron? ("Raised by Another") ("Maternity Leave")
• Why was it so urgent that Aaron be baptized? What did Charlie's dreams mean? ("Fire + Water")

For fan theories about these unanswered questions, see: Christian Shephard/Theories

• Why did Christian want a bodyguard while in Australia? ("Two for the Road")
• Why did Jack see Christian in the jungle? ("White Rabbit")
• Since Christian's coffin is empty, where is his body? ("White Rabbit")
• How does he converse with Vincent? ("So It Begins")
• Why did Hurley see him in Jacob's cabin? ("The Beginning of the End")

For fan theories about these unanswered questions, see: Danielle Rousseau/Theories

• Where is the ship Danielle and her expedition came on?
• Why is Danielle's clothing and equipment primarily military in nature if her "routine expedition" was scientific/medical?
• Who lit the brazier? If it was Danielle, how did she do it while on the other side of the Island, and why did Sayid see no footprints in the sand around it? If it was the Others, what was the smoke's purpose? ("Exodus, Part 1")
• What does the triangle on Danielle's map point to?
• What power source does Danielle use to recharge the batteries? ("Numbers")

For fan theories about these unanswered questions, see: Desmond Hume/Theories, Penelope Hume/Theories

• What happened to Desmond's father that forced Desmond to leave University before graduation to take care of his brothers? ("Flashes Before Your Eyes")
• What order did Desmond not follow that led to his dismissal in the army? ("Live Together, Die Alone")
• When Jack and Locke questioned the value of pushing the button, why didn't Desmond tell them about the System Failure he witnessed when the countdown timer reached zero? ("Live Together, Die Alone")
• Why didn't Desmond tell anyone about the fail-safe key, particularly in "Adrift"?
• What happened to Desmond during the discharge? Why was he naked but uninjured? ("Further Instructions")
• What is the nature of Desmond's flashes?

("Through the Looking Glass")

For fan theories about these unanswered questions, see: Henry Gale (original)/Theories

• How did Henry Gale die?
• Who buried him?
• Is his wife dead? If so, where is she buried?
• Was Henry's arrival on the Island just a coincidence?
• Why did Ben choose to steal Henry's identity?

For fan theories about these unanswered questions, see: Radzinsky/Theories

• Why did Radzinsky go to such great pains to conceal the map on the blast door? ("Live Together, Die Alone")
• Why did Radzinsky edit the orientation film? ("Live Together, Die Alone")

For fan theories about these unanswered questions, see: The Swan/Theories

• Why was there a Quarantine sign on the door? ("Man of Science, Man of Faith")
• What are the blast doors for? ("What Kate Did")("Lockdown")
• Why are the Numbers the code for pushing the button?
• What did the fail-safe do to the station?
• What caused the first lockdown to take place?
• Why was contact with the outside world strictly forbidden? ("What Kate Did")
• Where is the rest of the film? Why was it spliced so many times?
• If it imploded (as opposed to exploded) why were Desmond, Eko and Locke not crushed within it? ("Further Instructions")
• Why do Ben and the Others not take control of the Swan following the Purge and ensure continued input of the Numbers into the Computer instead leaving the task to Radzinsky, Kelvin, Desmond and later the Losties?

For fan theories about these unanswered questions, see: The Flame/Theories

• Was there another way to report an incursion by the Hostiles than first beating the computer at a chess game?
• Why did the Others leave the C4 still armed in the station?

For fan theories about these unanswered questions, see: The Pearl/Theories

• Why does the information sent via the pneumatic tube just end up in a pile in a meadow? ("Live Together, Die Alone")
• Who salted the earth, and was it their intention to make a question-mark shape?

For fan theories about these unanswered questions, see: The Door/Theories

• What is the purpose of this "station"?
• Which station is this on the Blast Door map, if indeed it is on there? ("Lockdown")
• Is there more to this "station" than a solid rock wall? ("Live Together, Die Alone")
• Is it entirely a ruse by the Others, or is it based on some truth (e.g. it was a real DHARMA logo)?

For fan theories about these unanswered questions, see: The Arrow/Theories

• Why is there a Quarantine sign on the door? ("...And Found")
• Who is the owner of the glass eye found here? ("The Other 48 Days")
• Who hid the Orientation video splice in the bible? ("What Kate Did")

For fan theories about these unanswered questions, see: The Staff/Theories

• Where does the escape hatch go?
• Why does the station have a secret room hidden behind some lockers? ("D.O.C.")

For fan theories about these unanswered questions, see: The Hydra/Theories

For fan theories about these unanswered questions, see: The "Monster"/Theories

• What is the the Monster?
• Is it controlled by someone or a free creature on the Island (if it is a creature, that is)?
• Why did it kill Seth Norris, the pilot? ("Pilot, Part 1")
• Why did it wait until meeting Eko for a second time to kill him? ("The Cost of Living")
• How and why does it uproot trees? ("Exodus, Part 2")("The 23rd Psalm")
• Is there a connection between the disappearance of Yemi's and Christian Shephard's bodies, their subsequent appearances on the Island, and the "Monster" (a connection alluded to by the writers themselves)? ("White Rabbit")("The Cost of Living")
• Why does the monster appear to take several different forms?
• Is there a connection between the chattering noise heard before Nikki is bitten by a Medusa spider, and the appearance of the spiders? ("Exposé")
• Why did the DHARMA Initiative or Kelvin and Radzinsky call the Monster "Cerberus"?

• Who are the dead bodies referred to by Locke as Adam and Eve? ("House of the Rising Sun")
• How did the Black Rock end up so far inland? ("Exodus, Part 1")
• Were there any survivors of the shipwreck of the Black Rock? If so, what happened to them?
• What culture and civilization does the four toed statue and stone wall artifact represent? What do the Others seem to know about them?

• What are the whispers?
• Why was "Elizabeth" whispered in the episode "Live Together, Die Alone" right before Sawyer got shot with a dart?
• Why do the monsoon rains seem to preclude particularly terrifying events?
• What caused the sudden rising tide in the episode "Whatever the Case May Be"? Sayid said "this can't be normal, the tide shifting so suddenly, rising in so short of time."
• When Charlie and Sayid finally found the fire that caused the pillar of black smoke in the Season 1 finale, Sayid makes the comment "there are no footprints" (around the fire). Why are there no footprints? How was the fire started? Who started the fire? ("Exodus, Part 2")

• How were the Flight 815 survivors able to survive the crash with only minor injuries? ("Pilot, Part 1")
• What is the sickness?
• What does the medicine do?

• Are the Losties really having visions and hallucinations; if they are, why?

For fan theories about these unanswered questions, see: DHARMA Initiative/Theories

• Why does DHARMA supply food with its own logo on it? Do they manufacture their own supplies? What is wrong with sending regular brands of food? Why not just send Mallomars, for example, instead of Dharmalars? ("Dave")
  • If canceled, why do the supply drops continue?
• What exactly is the DharmaTel network referenced on the blast door map? Is it still working?
• How did Kelvin come to work for the Initiative?
• Where are the DeGroots?

For fan theories about these unanswered questions, see: Hanso Foundation/Theories

• Why did the Hanso Foundation cut the DHARMA Initiative's funding in 1987 (as stated in the Lost Experience)? Why does Thomas Mittelwerk call the project a failure in 2006?

For fan theories about these unanswered questions, see: Widmore Corporation/Theories

• Whose pregnancy test did Sun use? ("The Whole Truth")
  • Is it connected to Bad Twin?

For fan theories about these unanswered questions, see: The Numbers/Theories

• Why do bad things happen to the people involved with the Numbers?
• What makes each number in the sequence so special?
• What do the numbers as "core values" of the Valenzetti equation actually correspond to, in terms of human and environmental factors as stated by Alvar Hanso? (I.e., does "4" stand for famine while "8" stands for disease, etc.?)
• Why is the voice broadcasting the numbers in The Little Prince different from the voice in all the other number transmissions?

For fan theories about these unanswered questions, see: Vaccine/Theories

• What is the sickness? Does it really exist?
• What relation is there between the sickness and the QUARANTINE signs on some DHARMA hatches?

For fan theories about these unanswered questions, see: Waving figure/Theories

• Who is this person linked to Jack, his father Christian, and half-sister Claire?