SEASON 1

Oceanic Airlines Flight 815, en route from Sydney to Los Angeles, crashes on a mysterious island. There are 48 survivors, and through a series of flashbacks, we learn about several of them.

Jack, a spinal surgeon. Locke, an office worker with dreams of adventure. Kate, a fugitive from the law. Sawyer, a con man. Claire, a pregnant woman. Charlie, a washed-up rock star. Hurley, an unlucky lottery winner. Sun and Jin, an estranged Korean couple. Sayid, a former Iraqi torturer. And Michael and Walt, a father and young son.

The survivors discover the island is full of surprises. They're attacked by a polar bear, Jack sees a vision of his dead father, and they hear strange whispers and other menacing sounds in the jungle. The death toll rises as other survivors perish while exploring the island.

Jack reluctantly assumes the leadership role, bringing some peace. Claire's baby, Aaron, is born. Locke begins to feel they were brought to the island for a reason—in part because he was in a wheelchair until the crash healed him. But Michael and others build a raft to try and escape.

They launch the raft, only to be confronted at sea by strange men who kidnap Walt and destroy the raft. Meanwhile, in the jungle, Locke finds a mysterious hatch, covering a ladder that leads deep underground.

SEASON 2

In the hatch, the survivors discover an old research station and its frantic occupant, Desmond. He says his job was to punch numbers into a computer—4, 8, 15, 16, 23, 42—every 108 minutes to save the world from ending. Locke becomes convinced that the task is his purpose on the island.

The people who were on the raft wash ashore and discover a whole new group: passengers from the tail section of their flight. Things on the island haven't gone well for them; several were kidnapped by people they call the Others.

If that weren't enough, the island is patrolled by a smoke monster that seems to judge people and kill those deemed unworthy.

The Others use Walt to force Michael into bringing Jack, Kate and Sawyer to them. Having betrayed his friends, he sails away with his son.

Meanwhile, Locke begins to doubt the importance of the computer and the hatch and decides to stop entering the numbers. Desmond panics and triggers a fail-safe that destroys the hatch and envelops the entire island in blinding white light. The incident is detected by people in the outside world who were looking for the island.

SEASON 3

The Others turn out to be living fairly conventional lives on the island, with houses and book clubs. They've occupied a number of scientific facilities, or stations, around the island that were built by the DHARMA Initiative. Their leader, Ben, says he takes orders from Jacob, an almost God-like being whom no one has seen.

Although the island has healing powers, its residents are not without health problems. Women die in childbirth and Ben has a tumor. Ben uses Sawyer and Kate to convince Jack to operate on him. Jack forces the Others to release Kate and Sawyer, and removes Ben's tumor in exchange for passage off the island on a submarine. Locke, however, is convinced that leaving the island would be a mistake and destroys the submarine.

Jack returns to camp with Juliet, who earns the group's trust by telling them of the Others' plan to kidnap their pregnant women. Meanwhile, they learn a freighter is offshore and try to make contact. Jack sets up an ambush and leads the survivors up a mountain to wait for rescue. Charlie is killed, moments after discovering that the freighter is not there to rescue them.

SEASON 4

It turns out the freighter was sent to kidnap Ben, leader of the Others, by a man named Charles Widmore. Widmore was Ben's predecessor but was banished from the island and became a wealthy industrialist.

Ben tells Locke that he was destined to be the next leader of the Others but that Widmore seeks to exploit the island's special properties. Locke seeks out Jacob and is told the only way to protect the island is to move it. He climbs down a deep well to turn an ancient wheel that taps directly into the island's mysterious energy.

Jack, Kate, Hurley, Sayid, Sun and baby Aaron are flown out to the freighter but abandon ship moments before it's destroyed by a bomb. Then, as they make their way back, the entire island disappears.

The group finds rescue and are dubbed the Oceanic Six. But back home, they are still haunted by the island.

SEASON 5

Locke, again using the ancient wheel, teleports off the island and tries to convince the Oceanic Six to come back. They refuse and Locke ends up dead. But Jack soon realizes he has to go back and is told he must bring Locke's body with him. They return to the island on Ajira Airlines Flight 316.

Locke is inexplicably resurrected and leads Ben to Jacob. Ben, frustrated by a lifetime of manipulation, kills Jacob.

Meanwhile, those left behind on the island jump through time and end up in the 1970s. They spend years inside the DHARMA Initiative, learning of the group's research into the island's powerful energy.

Jack concludes that he can reset time and stop the first plane crash from ever happening by detonating a hydrogen bomb deep underground. It doesn't go off at first, but Juliet falls in after it and hits it with a rock. There is another blinding white flash.

SEASON 6

There are now two time lines: a “;flash sideways”; in which Oceanic Flight 815 lands safely in Los Angeles, and the original universe on the island.

In the “;flash sideways,”; the survivors are leading slightly different lives but become increasingly aware that something happened to them.

On the island, the survivors are captured by what's left of the Others and Jacob's followers. It becomes apparent that each survivor had been selected long ago as candidates to succeed Jacob as caretaker of the island. That task entails keeping evil from escaping.

The evil is the smoke monster, which has taken on the form of Locke. Now, with Jacob dead, it wants to get off the island.

Widmore returns to the island in a submarine and says he also wants to stop evil from escaping. He's brought Desmond with him, because Desmond had survived direct contact with the island's energy in Season 1.

Jack comes to believe it's his destiny to stay on the island, but most of the other survivors want to go home. They try to trick the smoke monster and steal Widmore's submarine, but it's destroyed by a bomb. Jack, Kate, Hurley and Sawyer survive, but Sayid, Sun and Jin are killed.

Ryan Ozawa is a local “;Lost”; fan and blogger who, with his wife, Jen, produces “;The Transmission,”; a weekly podcast devoted to the show.