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.
After the Island
John Locke repeatedly visited Jack under the alias Jeremy Bentham, and when he landed on Jack’s operating table after an accident, he said Christian had told him to move the island. (“The Life and Death of Jeremy Bentham”)
Jack succumbed to depression and substance abuse, and his hospital suspended him. He began flying across the Pacific every weekend hoping it would crash, returning him to the island or killing him. When he heard Locke had killed himself, Jack tried calling Kate then almost leaped off an L.A. bridge, distracting a driver he then had to save from the ensuing crash. (“Through the Looking Glass, Part 1”)
A doctor refused to let him operate on the passenger he’d saved, and when a pharmacist denied him painkillers, even when he forged a prescription from his father, the same doctor caught him trying to steal drugs. Jack finally managed to meet Kate outside the airport and said they had to return to the island. Kate refused and drove away.
He attended Locke’s funeral but no one else did. (“Through the Looking Glass, Part 2”)
He later broke into the funeral home, where Ben appeared. He said that all of them, even dead Locke, had to return to the island. (“There’s No Place Like Home, Parts 3”)
5×01 – Because You Left
They removed the coffin then they went to a hotel where Jack shaved his beard and Ben flushed his pills. They then watched Hurley’s arrest on the television for multiple murders. (“Because You Left”)
5×02 – The Lie
Later, Hurley contacted Jack, and his father brought him Sayid’s unconscious body. Jack successfully treated him at St. Sebastian Hospital, though an administrator reminded him of his suspension. (“The Lie”)
5×04 – The Little Prince
A kidnapper with Kate’s address in his pocket also attacked Sayid, and when Jack told Kate, he learned a lawyer knew she wasn’t Aaron’s mother. Jack and Kate followed the lawyer to Carole Littleton’s motel, but Jack learned she hired him for an unrelated case. They drove next to meet Ben at the marina, where Jack failed to convince Kate to stay and listen. (“The Little Prince”)
5×06 – 316
Ben led Jack to a church, where Eloise Hawking showed the group the DHARMA station that first found the Island. She told them to take Ajira Airways Flight 316 to return to the Island. She privately gave Jack Locke’s suicide note and told him to give Locke’s body something that had belonged to Christian.
Jack obeyed by collecting Christian’s shoes from his grandfather, who’d been trying to escape his retirement home, and placing them on Locke’s feet along with the note. On the eve of the flight, Kate slept with him, agreeing to come to the island.
At the airport, Caesar offered him condolences over his loss, and in the plane, an attendant handed Jack the suicide note. They took off, and jack realized Frank Lapidus was piloting and said hello.
Further on the journey, he read John Locke’s note, which read, “Jack, I wish you had believed me. JL.” The flight suddenly encountered heavy turbulence, and was then surrounded by a bright light. (“316”)
Back on the Island
5×06 – 316
Jack woke up in the middle of the jungle as he had when he first crashed on the Island. He found Hurley and Kate at the waterfall, and Jin found them and called Sawyer. (“316”)
5×08 – LaFleur
Jin drove Jack, Hurley & Kate in the DHARMA van to the Northern Valley shoreside meadow where they reunited with Sawyer. (“LaFleur”)
5×09 – Namaste
Jack learned they had traveled back in time to when the DHARMA Initiative occupied the island, and Sawyer and Juliet inducted them as new recruits. Jack became a workman.
He visited Sawyer that night at his and Juliet’s house, admitting that Sawyer, now DHARMA’s security head, was in charge. (“Namaste”)
5×10 – He’s Our You
When a flaming DHARMA van crashed into a house, Jack helped extinguish it with a fire hose. (“He’s Our You”)
5×11 – Whatever Happened, Happened
Horace accused Sayid, who’d been locked up, and Jack disagreed, arousing his suspicion. When DHARMA found a janitor’s keys in Sayid’s cell’s lock, they put Jack, along with Hurley and Kate, under house arrest. Sawyer tried to recruit Jack’s help operating on young Ben, who’d been shot, but Jack, done with trying to fix things and now trusting in the Island, refused. This angered Juliet, who resented his return, and Kate, who claimed to prefer “the old” Jack. (“Whatever Happened, Happened”)
5×13 – Some Like It Hoth
Jack covered Roger’s work, and defended Kate when he accused her. (“Some Like It Hoth”)
5×14 – The Variable
Early the next morning, Daniel Faraday showed up at Jack’s house claiming Jack did not belong there. Daniel told Jack that his mother was wrong, and that Jack does not belong there. Jack visited Sawyer, who revealed that he’d tied up a DHARMA member who’d discovered he’d taken Ben to the Hostiles. Jack, Kate, Sawyer, Juliet, Jin, and Hurley all met in Sawyer and Juliet’s home to discuss their options. Miles and Daniel then, asking to visit the hostiles to find Daniel’s mother. Jack, Kate, and Daniel went to the motor pool for weapons DHARMA workers opened fire, and Jack shot a fuel tank so they could escape.
Daniel explained his plan to detonate a bomb at the Swan, then entered the Hostiles’ camp where Faraday was shot and killed by Eloise. (“The Variable”)
5×15 – Follow the Leader
Inside the Hostiles’ camp, Charles Widmore knocked out Jack with his rifle’s butt. Jack later explained Daniel’s plan to Eloise, and they swam to the underground tunnels where the bomb was hidden. (“Follow the Leader”)
5×16 – The Incident, Part 1
Sayid, who’d joined them, extracted the bomb’s core, and he and Jack entered Horace’s house through a passage Richard created. They donned DHARMA jumpsuits, and Jack shot three Initiative members after one shot Sayid. Hurley picked them up in a van, and Jack tried to treat Sayid inside. They drove till they say Sawyer, Juliet and Kate in the road. Sawyer and Jack argued in private about whether to detonate the bomb, then they fought intensely till Juliet separated them. (“The Incident, Part 1”)
5×17 – The Incident, Part 2
The van drove to the Swan site, and Jack entered it alone with the bomb. Phil spotted him, and the van started attacking from afar. Jack shot one member, and he and the others successfully neutralized all present. Jack dropped the bomb into the Swan drilling shaft. Nothing initially happened, then a severe electromagnetic Incident pulled all metal objects into the shaft, including a tool box that knocked Jack out. He awoke to find Kate pulling Sawyer away from the drilling shaft, which Juliet had just fallen down. Jack helped, and moments later, the bomb presumably detonated. (“The Incident, Part 2”)