The Bésixdouze expedition was a group of six French researchers, including Danielle Rousseau, who sailed from Tahiti on November 15, 1987. Their ship, the Bésixdouze, wrecked near the Island during a storm while the expedition was attempting to locate the source of a strange transmission. Pieces of wreckage from the vessel washed ashore. All members of the expedition, with the exception of Danielle Rousseau, died later that same year. At the time of their arrival, Danielle was already seven months pregnant with her daughter, Alex.
While the team was in the water, their radio picked up a transmission. It was a voice continuously repeating a set of numbers. The Bésixdouze tried to find the source of the transmission, but their ship got caught in a storm and eventually ran aground, with the hull breached beyond repair. By February 1988, they were drifting to shore in an emergency raft when they came across Jin floating unconscious in the water, following the explosion of the Kahana and the time shifts. They dragged him into the raft and brought him to shore with them. ("The Little Prince")
Jin regained consciousness onshore and through his limited English, tried to explain that his ship exploded, which they interpreted as meaning it was wrecked in the same storm they were caught in. Though disoriented, Jin insisted he needed to find his camp, surprising them. Robert, by drawing a tower in the sand, asked Jin if he knew of a radio tower on the Island, which he confirmed. The team continued searching for the transmission that brought them to the Island, hoping they can use it to call for help.
Jin agreed to lead them to the radio tower because he did not know the way to his own camp from his current location, but would once he arrived at the tower. On the way there, Nadine went missing. While searching for her, the team heard a noise, which Jin identified as the Monster. Moments later, a tree was torn up and Nadine's dead body fell to the ground. Jin yelled at the group to run as the smoke monster made its way through the trees. The Smoke Monster caught Montand and dragged him through the jungle to a declivity in the Temple wall. The group chased him and managed to grab his arm just before the monster pulled Montand down the hole. As they struggled, a tentacle of smoke wrapped itself around Montand's arm, severing it. When they heard Montand calling from the hole, saying he had been wounded and needed help, the members of the science expedition decided to enter the hole, despite Jin's warning to the contrary. Jin convinced Danielle to remain behind for the sake of her baby. As they waited, Jin experienced a time flash and disappeared. ("This Place Is Death")
Two months later, Jin returned through another time flash, and found the corpses of Brennan and Lacombe on the beach. Then he saw Danielle on the beach arguing with Robert. She claimed he was not Robert and that he had become infected by the monster. Robert tried to assure her that he still loved her and had not changed. He insisted that the smoke monster was merely a security system for the Temple. Robert pleaded with her to put down her gun, saying how much he loved her and their baby. She began to lower her weapon, but Robert raised his own and pulled the trigger. The gun failed to fire because Danielle had removed the firing pin, which Robert suddenly realized in shock. She immediately shot Robert in the head and Jin cried out in alarm. ("This Place Is Death")
Danielle turned toward him and recognized him. Insisting that he too was infected and that he was "a carrier," she began firing at him. Jin rushed into the jungle to hide and experienced another time flash. ("This Place Is Death")
Danielle, the last member of the expedition, gave birth to her daughter alone three days later. One week later, her baby was kidnapped by Ben and Ethan. Danielle survived alone, building elaborate defenses to protect herself from the Others, and meets nobody else until she captured Sayid in October 2004. ("Solitary")
Danielle was one of the two women on the team, and was pregnant with the daughter of fellow team member Robert. Due to the "sickness," she killed several members of her team until she was the last remaining. She survived on the island in seclusion for sixteen years afterward until she was killed by the mercenary team.
The father of Danielle's then-unborn child, Robert arrived on the island with the science team, and was eventually shot and killed by Danielle due to him having the "sickness."
According to the timeline, the transmission they hear appears to be the same transmission picked up by Sam Toomey and Leonard Simms at their listening station in 1988.
The expedition's vessel was named Bésixdouze, French for B-6-12 (bé six douze) either purposely or coincidentally the same name of the Prince's asteroid, B612, in Antoine de Saint-Exupéry's novella The Little Prince from 1943.
↑Danielle's words in "The Little Prince" suggest they set out in 1988, but script coordinator Gregg Nations confirms that she referred to the current year, in response to Jin's demanding "What year?" and not the year of their departure date.