Sixteen years before Oceanic 815 crashes on the island, Rousseau was a heavily pregnant member of a six-person crew aboard a French research vessel three days out of Tahiti. The crew picked up a radio signal emanating from the South Pacific, which was a repeating set of six numbers: 4, 8, 15, 16, 23 and 42. While attempting to find the source of the signal, the ship ran aground on rocks surrounding the island. Before reaching the shore, Rousseau and her team found Oceanic 815 survivor Jin-Soo Kwon (Daniel Dae Kim) in the water, who had been time-travelling as a result of the time shifts which had been moving him and the flight survivors through the island's history.