When flight 387 goes down due to a terrorist bomb, only two survive the crash. Richard Buchanan a mechanic from Pittsburgh is traveling to China for a job, since he is unemployable at home. Susan Ryan a Surgeon from Cleveland on the same flight is on her way to do charity work in Indonesia for a break from her controlling family and fiancé.Together, they build a raft from floating shipping boxes before the wing goes down. On the fifth day, they are out of water and have only caught one fish during that time. They are beginning to irritate each other, but then she suggests they make love, since they will soon die together.Their raft being driven by currents and storms brings them to Bokak Atoll, which is a deserted island. Unknown to them, an old pirate was hiding on the island guarding a plunder of drugs. While searching for water, the two find a cave that two Japanese spotters used during WW II and find Ishi's swords. The swords were made by a famous sword maker and are considered a treasure in japan.They discover the old pirate Jean in their Lean-to. He is sick and malnourished. Susan treats him as best she could with the little they salvaged. The old bearded man becomes their friend and lies about how he became stranded on the island. He also spots Rich's tattoo and brings out Rich's background. He'd been wrongly convicted of a crime and joined a gang while serving time. Only when his partner Gilly finally comes to pick him and the drugs up, is his story blown. Jean's partner is a psyco and doesn't want witnesses. When his men try to kill the couple, Rich uses the sword known as Cherry Blossom to dispatch two and scare off a third.With prospects of the pirates coming back, Rich accelerates his plan to build a bigger, sail driven raft. When the raft is nearly finished, he is bitten by a small shark while retrieving a sail. Susan treats his wounds and helps finish the raft. By now, she has feelings for him and afraid he will die from infection.After a few days on the raft, a boat is spotted behind them and Rich is feverish. She worries the boat is the pirates, because it is the same type of boat Gilly has. Signaling planes with a mirror as planned, she hopes he will live. When she sets off a homemade flare, the boat behind comes to their aid. The Yamora family was heading back to port when they saw the flare and they become friends with the couple as a result of their assistance.They stop at the hospital to check rich's latest blood work and get antibiotics. She has a shock when the clerk also gives her blood work results. According to her tests, she is pregnant with his child.Rich recovers quickly, but news is portraying them as unlikely lovers. The news deepens their insecurity about their relationship, but they are stuck in japan until they can get new passports. They take up the offer to spend a few days on a commercial fishing boat with their new friends. It turns out to be a great trip with full holds. On the way back, Rich can't stand the confinement of their small cabin and fishes with a rod. He catches a near record size marlin and they head haply toward the fish auction.Nearing Tokyo, they have to go through narrows where boat traffic slows them down. Gilly and his men take advantage and attack the fishing trawler loaded down and with a huge fish tied to the stern. Rich is shot, but comes up with a plan to stop the pirates. He uses the fishing gear and ropes to entangle his prize catch in the props of the pursuing boat. While treating Rich at Tokyo General, her fiance shows up and reinforces her decision to be with Rich by trying to control her. She is concerned that Rich won't make it, because he is long overdue to wake up. A police Sargent brings Rich's swords to the hospital when they are released. He tells Susan a sword can help its owner and she is surprised when he improves while his hand rests on the antique sword.