The Providence, a Scottish trawler, unloads at a Belgian port. Once again, it has failed to catch enough to pay the mortgage. The Skipper is old, and has long left all financial responsibility to his son, Sean. Faced with bankruptcy, Sean reluctantly accepts a lucrative offer – smuggling Chinese immigrants over the North Sea to Britain.
Lured by the easy money, Riley, a deckhand, is all too willing to help. Sean is too ashamed to tell his father, though. While the Skipper sleeps, the Chinese are all loaded into the hold. All but one, that is. The youngest, Su Li, a girl of just 11, slips away below decks. Soon the slow-witted Cook notices food disappearing from his galley. He begins a silent hunt for the intruder.
At sea, Riley is put in charge of looking after the Chinese. He feels increasingly uneasy. They have to catch some fish before they can head home – otherwise they are bound to be searched by customs. Again and again, though, the net comes up empty. And all the time, conditions in the hold are deteriorating.
Increasingly desperate, Riley and Sean work themselves to exhaustion, even braving an appalling storm to rescue the net. Still no fish. When one of the Chinese dies in the hold, The Skipper witnesses Sean disposing of the body over the side of the trawler.
The Skipper confronts his son. But Sean was only ever trying to keep his father’s pride and ship afloat. For the first time, the Skipper is forced to acknowledge his own failure. Broken, he gives up the wheel – and his ship – to his son. Sean sets course for home. With no catch, the Chinese will be caught and the ship confiscated, but Sean has no choice: Someone has died.
On the homeward journey, though, Sean picks up a strong sonar signal. He lets down the nets and brings up a magnificent haul. Both the Providence and the Chinese seem saved. Sean opens the nets. Out come prime cod - and human bodies. The Skipper has taken drastic measures to stop his son losing his rightful inheritance. He flooded the hold, drowning the Chinese, and threw the bodies overboard. Inevitably, some of the corpses landed in the net.
Meanwhile, the Cook has finally caught Su Li. When the Skipper sees the girl, he breaks down in remorse. She is a witness. For a split second, it seems as if he might even try to hurt her too. And then he is felled by a heavy chain wielded by the Cook. He dies in Sean’s arms.
Of the twenty would-be immigrants, only Su Li ever sets eyes on Britain.