The Line is a spot designated in the jungle by Tom. He warned cryptically that if the castaways were to cross it, they go from a misunderstanding to "something else". ("The Hunting Party") A flashback to this same event from the Others' point of view occurred in Michael's flashback in "Three Minutes".
The line was visited by Jack and Kate in an attempt to arrange a prisoner exchange between Walt and Ben. Jack yelled until he lost his voice, and while they waited for his voice to recover, Michael stumbled out of the jungle. ("S.O.S.")
There was a black rock visible at the line when Jack was calling for the Others. ("S.O.S.") Claire wrote in her diary that she had a dream about a black rock which she couldn't get away from. ("Special") The crashed ship on the Island was also called the Black Rock.
- For fan theories about these unanswered questions, see: The Line/Theories
- Where is this line in relation to other places on the Island, such as the balloon, the Arrow, etc? Did the journeys to any of these places cause characters to cross it?