Bernard Nadler is a tail section survivor of the crash of Oceanic Flight 815 and the husband of Rose. He is the only tail section survivor that has not been captured by the Others or killed. He wasn't seated in the tail section, and was only there when the plane crashed because he was using the bathroom. Bernard cares very much for Rose and feels a need to fix things, like her cancer, not dissimilar to Jack. After time-travelling to 1977, Bernard and Rose live in peaceful seclusion in a cabin near the beach.
Bernard had been a bachelor for 56 years when he met Rose. Her car was stuck in the snow and he offered to help her out. When the car emerged from the snow, Rose proposed to buy him a cup of coffee to thank him. Bernard proposed to her at Niagara Falls after dating for just five months. Rose told him that due to a terminal illness she only had one year left to live and asked him if he is sure he still wanted to marry her. Bernard was not deterred, and during their honeymoon, he took Rose to a faith healer in Australia hoping that she would be cured of her illness. The healer, Isaac of Uluru, told Rose he couldn't help her. Rose lied to Bernard and told him she was cured so they could enjoy their remaining time together. ("S.O.S.")
Bernard was sitting in seat 23E on the plane, but left to go to the bathroom shortly before the turbulence started. As a result, he ended up in the tail section of the plane when it broke off. Since his fingers were prone to swelling when he flew, he had left his wedding ring with Rose. ("Pilot, Part 1")
After the crash, Bernard was found high up in a tree, still strapped into a broken-off seat. Goodwin spotted him and called for Ana Lucia, who calmed him down so he could safely descend. ("The Other 48 Days")
Bernard was very worried about Rose after he could not find her or her body anywhere on the beach. As the tail-section survivors were kidnapped by the Others over the following weeks, Bernard found himself among the few remaining. He was one of the few tail section survivors, or Tailies, left to meet Michael, Jin, and Sawyer from the middle section.
Bernard and the Tailies found the Arrow station and used it for shelter and protection from the Others. In the Arrow, Bernard found a working radio. He used it and made contact with someone claiming to be another survivor of the plane crash (Boone). Ana Lucia thought it was the Others trying to trick them and ended the transmission. Bernard later gave the radio to Hurley. ("Deus Ex Machina") ("The Other 48 Days")
Later, Bernard and the other Tailies caught Sawyer, Michael, and Jin and held them in a pit. After Ana Lucia found out they weren't Others, she brought them to the Arrow, where Bernard approached Sawyer, Michael, and Jin and asked if there was a woman named Rose where they had come from. Bernard was elated when Michael and Sawyer told him that Rose was still alive on the other side of the Island. ("Everybody Hates Hugo")
The next day, the Tailies decided to go to the middle section camp. Before the long hike, Bernard, Ana Lucia, and Jin tried to catch fish, though Jin was the only one who had any success. They then began the long trek. ("...And Found") ("Abandoned")Upon approaching the middle section camp, Ana Lucia accidentally shot and killed Shannon, and demanded that Bernard and everyone else not to go back to camp.
Two weeks later, Rose and Bernard were bickering because Bernard had forgotten his wife's birthday. They stumbled upon Sun vomiting. Sun told them she was just feeling lightheaded. Later, Bernard was trying to ask Jin for an oyster for Rose's birthday when Sawyer approached to tell Jin that Sun was pregnant. ("The Whole Truth")
Following the DHARMA food drop, Rose took leadership and organized the food. Bernard commented that she was acting like she "just got back from the store." After this, he came up with the idea of making an SOS sign to be spotted by aircraft flying overhead. He gathered a group together for a meeting in which he told them they have given up getting rescued. Unfortunately, Rose interrupted and told him he should confer with Jack. Bernard got angry and told her Jack was just a doctor. Rose then embarrassed Bernard in front of the group by telling him he was only a dentist. ("S.O.S.")Only 15 people came to help build the SOS sign. Bernard delegated himself the easy job of marking the letters in the sand, while everyone else dragged heavy rocks to the shore. Later, Bernard told Rose about people not helping and asked her why she wasn't supporting him. They began to argue and Bernard told her, "If I didn't always have to do something you wouldn't be here." Rose then walked away, and Bernard seemed to realize that he was out of line. After he criticized Jin's method of building the sign, Jin left the project, and Bernard was on his own. Rose approached Bernard and apologized, and told him Isaac hadn't healed her.
During the discharge, Bernard held his ears. Just after, he moved Claire and Aaron to safety, helping them to avoid being hit by the quarantine door. Later, Bernard was helping clean up the mess from the discharge when Charlie came out of the jungle. Bernard asked him what had happened and if he was okay. ("Live Together, Die Alone")
Following the implosion of the Swan station and the capture of Jack, Kate, and Sawyer, Bernard and Rose became less active among the survivors than they were before. At one point, Sawyer stole a Phil Collins tape from Bernard to give to Kate as a "mixtape." ("Catch-22")
When Karl and Juliet informed the survivors of the imminent attack of the Others, a plan to fight back was hastily created. Rousseau retrieved dynamite from the Black Rock and Rose and Bernard searched through the plane wreckage to find wire for detonating the dynamite. The pieces of wire had to be strongly knotted together into longer lengths, which Bernard seemed to have trouble doing well. Rose, who was much more successful at the task, showed Bernard how to knot them correctly. When the survivors realized they needed three shooters to detonate the dynamite, Bernard volunteered and proved his shooting skill to Rose and Sayid by shooting cans of DHARMA food. ("Greatest Hits")
Before leaving for the radio tower, Rose reminded Bernard that he was "not Rambo," and to be careful. Bernard and Sayid successfully shot their tents, setting off the dynamite explosions and killing seven Others. Jin missed, however, and Bernard ran into the jungle where he was caught by Tom, as Ryan and Jason captured Jin and Sayid. Bernard was forced to tell Tom what he knew of the plan concerning the radio tower in order to save Jin, whom Tom had been told to kill if his questions weren't answered. Later, Tom shot three rounds into the sand as part of a ploy to convince Jack (listening on Ben's radio) that his friends had been killed. Hurley then showed up in the DHARMA van, allowing the remaining Others to be killed, and saving Bernard. Later, Bernard looked on happily as he sat on the beach. ("Through the Looking Glass")
While Bernard stood on the beach, Hurley told him about the transmission to the freighter. He then urged Hurley to do a cannonball, which Hurley did. Desmond rowed ashore and revealed that Charlie had died. The group left the beach to meet everyone at the cockpit, where Bernard was reunited with Rose. He asked her if she wanted to go with Locke and stay on the Island, but Rose preferred to stay with Jack. ("The Beginning of the End")
Several days later, Bernard encountered Jin and Sun on the beach, and asked if he could go fishing with Jin before realizing that Sun was crying and he had intruded on an emotional moment. Jin, however, still invited him to come along, preferring not to talk about Juliet's revelation of Sun's affair with Jae Lee. While fishing from the outrigger, Bernard observed that he and Jin were the only men with wives on the Island, then confided Jin about Rose's cancer and her desire to remain on the Island, and his confusion over Rose's decision, then, to stay on the beach, though he also calls Locke a murderer. In the end, Bernard said, it all comes down to karma. Bernard's taking life in stride out of his devotion to Rose reminded Jin of his own renewed love for Sun, and he returned to her on the beach that night. ("Ji Yeon")
The next day, Bernard was at the beach when he noticed something strange in the water. Bernard called for help, bringing the attention of Jack, Kate and Juliet. Vincent was also there, barking madly. All of them fished a body out of the water. Daniel and Charlotte came forward, and when Jack asked who the person was, Daniel identified the body as Ray, the freighter's doctor. They realized that they needed to communicate with the freighter; however, the sat phone was broken. Daniel said he could repair the phone enough to transmit Morse code if he could get the right materials. During the repairs, Jack called Bernard aside to discuss something. Presumably, Jack asked Bernard if he knew Morse Code and if he would translate Daniel's message.
Bernard was present when Daniel used the sat phone to send and receive a Morse Code message. When Daniel lied about the content of the message, Bernard corrected him in front of the group. Daniel claimed the message said, "Friends are fine. Helicopters coming in the morning," but Bernard said the real message was, "What are you talking about? Doctor is fine." Jack then threatened Daniel and demanded to know the truth. Bernard, along with the group, was shocked to learn that Daniel and Charlotte had lied about ever taking them off the Island and that rescue was never coming from the Freighter. ("The Shape of Things to Come")
The next day, Bernard and Rose continued to interrogate Daniel and Charlotte, eventually leading to an argument. Jack calmed them down, but collapsed after. Bernard volunteered to help Juliet with Jack's appendectomy. As Bernard and Rose washed down a table surgery, they discussed Jack's surgery and the fact he got sick despite the Island's healing powers. During the surgery, Bernard administered the local anesthesia to enable Jack to assist with his surgery. After the pain became too great for Jack, Bernard used a chloroform rag to knock Jack out. Post-surgery, Bernard went outside and told Kate it was all right for her to return inside the tent. ("Something Nice Back Home")
After the Island moved through time, Bernard and Rose were separated from each other, eventually reuniting at the beach along with Sawyer and Juliet. Sawyer tried to calm them down, but Bernard revealed to him that the beach camp had disappeared, leaving only the survivors behind. ("Because You Left")
Bernard remained at the camp, making multiple attempts to create fire, arguing with Rose over ways to do so. Neil berated them both, telling them that they had things to worry about other than fires. Bernard was able to make a small fire after several hours of trying, but his small flame is soon extinguished by the wind. Neil took this opportunity to vent his rage at the incompetence of Bernard and the other survivors. Neil's tirade ended, however, when he was shot in the chest by a flaming arrow. More volleys of arrows soon followed, killing three more survivors. Rose and Bernard were among those who were not killed, and made their way into the jungle. ("The Lie")
Rose and Bernard later emerged when Sawyer, Kate, and Juliet escaped from the sub. They revealed their small cabin which they having been living out of for the past three years. They expressed that they were happy living peacefully on their own, away from the violence and drama that the other survivors had always been involved with. Although unstated, the middle-aged couple had obviously been left alone by the Monster. Bernard, with an unkempt appearance, appeared much more relaxed than his former anxious self. The man who once assisted in ambushing The Others now expressed that he was simply happy with the time he has, and showed no concern about the possibility of a nuclear explosion. He stayed with Rose at their cabin, and said farewell to his old friends. ("The Incident, Parts 1 & 2")