Dr. Jack Shephard was a spinal surgeon and the survivors’ de facto leader. Before the crash, his obsessive personality wrecked his marriage and his relationship with his father. On the Island though, the survivors sought his guidance during many crises and missions, and he united them until they cooperated and formed a society.
Jack developed romantic relationships with Kate and later Juliet, and his jealousy sparked a rivalry with Sawyer. His rationality, so useful when solving problems, prevented his accepting the Island’s mystic properties and caused friction with “man of faith” John Locke. Problems arose that Jack could not fix despite his obsession and self-sacrifice. Though he tried to repress his guilt, he often broke out with violence or tears.
After suffering a kidnapping and almost negotiating his own rescue, Jack escaped the Island with five other survivors. Off-island, he laid his father to rest and proposed to Kate, but visits from John Locke and his father’s ghost sent him toward depression and substance abuse. Yet he gained new faith, and he led the survivors back to the island, believing it was his destiny. He then found himself in the past, where he tried to reset his and the others’ lives and prevent the crash of Oceanic 815.
The attempt failed, sending Jack to a new low. But after discovering he was a candidate to replace Jacob as Protector of the island, he gained confidence and decided to stay on the island. He also ceded decision-making to Sawyer, overcoming his control issues. He chose to become the Island’s new protector and was almost killed by the Man in Black, but with Kate’s help, he killed him before he could leave. He then sacrificed himself to relight the Heart, saving the Island from destruction. Post-death, he imagined a son and an ex-wife to come to terms with his bad relationships. His personality mixed science and faith, but he again felt the compulsion to fix others. His stubbornness returned, and unlike his friends, he resisted remembering his life, even after experiencing flashes. Eventually though, he remembered everything and after seeing his father again, he was able to “let go”, reuniting with Kate and his friends, to finally move on in the church.
3×01 – A Tale of Two Cities
The Others took Jack’s blood and imprisoned him in a disused aquarium, where he tried to assault his interrogator, Juliet. When she refused his orders to open a door, he unlatched it himself, flooding the corridor. He managed to close it again, and she knocked him out and returned him to his room. Juliet then revealed that she had a details on his life. (“A Tale of Two Cities”)
3×02 – The Glass Ballerina
Jack later met with Henry, actually named Benjamin Linus, who proved the Others had contact with the outside world by playing news footage of the Boston Red Sox winning the World Series. He then offered Jack a trip home in exchange for his cooperation. (“The Glass Ballerina”)
3×04 – Every Man for Himself
When Colleen arrived with a gunshot wound, Juliet demanded Jack’s help. He failed to save her, but he noticed an x-ray while washing up. (“Every Man for Himself”)
3×05 – The Cost of Living
Ben brought Jack along to Colleen’s funeral, held at the beach where her body was burnt on a floating pyre. He conned Ben into admitting it was his and this apparently disrupted Ben’s plan to pressure Jack into operating on him.
Juliet sent Jack a secret video message suggesting he kill Ben while operating. (“The Cost of Living”)
3×06 – I Do
Juliet brought in Kate, who begged Jack operate so the Others would spare Sawyer. Jack later found his door unlocked, letting him collect a pistol from a weapons locker and spied on Kate and Sawyer sleeping together on a security monitor. Jack now agreed to operate, but he deliberately cut Ben’s kidney sack during surgery, threatening to bleed Ben to death unless the Others freed Sawyer and Kate. (“I Do”)
3×07 – Not in Portland
The Others agreed, and Jack only completed the surgery when Kate repeated a story to prove she was safe. Jack told her not to return for him. In the operating room, Jack revealed Juliet’s plan to kill Ben. (“Not in Portland”)
3×09 – Stranger in a Strange Land
After the surgery the Others locked him in Sawyer’s old cage, and the Others’ sheriff asked him for more details. Jack lied on her behalf then offered Ben further medical treatment if he let Juliet live. Ben agreed. The Others took Jack with them to the Barracks. (“Stranger in a Strange Land”)
Mobisode x03 – King of the Castle | 3×12 – Par Avion
During his week there, he played chess with Ben and played football with Tom, shocking Kate and Sayid when they came to rescue him. (“King of the Castle”) (“Par Avion”)
3×13 – The Man from Tallahassee
Kate got captured during this rescue attempt, and Jack visited her, speaking of his deal to leave the island. This deal fell apart when Locke sabotaged the Others’ submarine. (“The Man from Tallahassee”)
3×15 – Left Behind
The Others abandoned the Barracks, leaving Juliet behind, and Jack took her back to the camp, telling the survivors she was under his protection. (“Left Behind”)
3×16 – One of Us
The survivors mistrusted Juliet and lost their trust in Jack as well. (“One of Us”)
3×19 – The Brig
Kate finally approached Jack about a parachutist that had entered the camp. (“The Brig”)
3×20 – The Man Behind the Curtain | Mobisode x05 – Operation: Sleeper
Sayid approached him about Juliet’s being Ben’s mole – a secret Jack already knew. (“The Man Behind the Curtain”) (“Operation: Sleeper”)
3×21 – Greatest Hits
Jack revealed that he, Rousseau, and Juliet had been planning to use dynamite to lay a trap for the Others.
When he learned the Others were coming sooner than expected though, he decided to lead most of the survivors to the radio tower, leaving just three behind to set off the trap. (“Greatest Hits”)
When Juliet and Sawyer announced that they were returning to the beach, Jack kissed Juliet as Kate looked on, but he told Kate he loved her soon after. (“Through the Looking Glass, Part 1”)
Ben and Alex intercepted the group, and Ben privately told Jack Naomi’s people planned to kill everyone on the island. When Jack did not cooperate, Ben ordered by walkie-talkie the deaths of three hostages – Sayid, Jin and Bernard. Jack savagely beat Ben, but later learned the hostages were fine.
When the group reached the radio tower, Locke stabbed Naomi and held Jack at gunpoint, but Jack ignored his threats and called Naomi’s boat. A man answered and told Jack rescue was on the way. (“Through the Looking Glass, Part 2”)