Plot
In 1954 Scotland, shiftless young drifter Joe Taylor works on a coal barge which operates from Glasgow, on the River Clyde, along the Forth and Clyde and Union Canals to Edinburgh. He shares the cramped on-board living quarters with its owners and operators, husband and wife Les and Ella Gault, and their young son Jim.
One day, Joe and Les pull the body of a young woman, Cathy Dimly, naked except for a petticoat, from the water, they cover her and hand the body over to the authorities. After Cathy's body has been taken away by the police, Joe and Les sit on the barge discussint theories as to what happened to Cathy. In a flashback it is revealed that Joe has seen Les and Ella having problems in the bedroom, with Les' drinking making him unable to perform. Joe goes into explicit detail theorising what may have happened to Cathy, with Ella present. Joe and Les work for the day, before washing and agreeing to go to a nearby pub to play darts. As they sit on the barge after dinner, Joe caresses Ella under the table. Joe and Les go the pub and sit there chatting with other patrons about Cathy, before Joe makes his excuses to leave and return to the barge. Back on the barge, Joe makes an advance on Ella, who succumbs, and not wanting to disturb the sleeping Jim, the two go outside the barge to have sex on the towpath. Les returns and initially senses an atmosphere between Joe and Ella, although when Ella snaps at him he changes the subject back to Cathy.
In the past, it turns out that despite not having said anything about knowing her, Joe knew Cathy, an office worker. The two had met on a beach, with an immediate attraction between them. In the present, Jim falls off the barge into an oncoming barge, Joe swiftly dives into the water and rescues him. The Gaults, and Joe, go to an amusement arcade together. The arcade closes due to heavy rain, with Les, Jim and a friend going off to the cinema, and Joe going back to the barge. Despite initially resisting him, Ella and Joe have sex once more.
In the past, Joe and Cathy meet by chance, and reflect on the end of their relationship, and Joe's unrealised plans to move to China. They go to the waterfront and have passionate sex beneath a parked truck.
Joe and Ella's relationship becomes ever more daring, with the two engaging in passionate clinches while Les is up on deck.
In the past, on the waterfront, Cathy reveals she is two months pregnant with Joe's child. This causes an argument between them, in which Cathy reveals she has been seeing another man, a plumber called Dan. When Joe begins to walk off, she runs after him, when she reaches for his arm to hold and he withdraws it, she trips and falls into the cold water while dressed only in her petticoat. Joe stays on the embankment, repeating her name several times, but making no move to rescue her and when she fails to surface, he panics, disposes of her belongings, and runs away.
Joe is still traumatised by the loss of Cathy, carrying her photo, and the engraved mirror from her, with him at all times. The newspaper reports that Daniel Gordon, the plumber whom Cathy was casually seeing, has been arrested and is being tried for her murder. The lack of discreation between Joe and Ella results in Les finding out about their affair. After initially losing his temper, Les calms down and agrees to move out of the barge, which belongs to Ella. Ella and Joe drift into a more serious relationship, although much of the appeal has gone for Joe.
In the past, Joe and Cathy are on a boat on a lake, Joe rocks the boat which makes Cathy afraid as she can't swim, before the couple make love on the boat.
Joe is rapidly losing interest in his relationship with Ella, with the two having a disagreement over Cathy's death, and the upcoming court hearing of the accused, Daniel Gordon. Joe is ready to tell Ella the truth about his relationship with Cathy, but Ella is not interested. Joe has now taken over all Les' duties on the barge.
We see a typewriter on the canal bed. In the past, Joe is sitting at a typewriter, struggling to write.
Les meets the barge on an embankment to collect his things, which Joe gives him. Joe offers Les a cup of tea, but Ella sends him back to work. Les says that he has been called as a witness in the court case relating to Cathy's death. Ella states her intention to go to a lawyer and formalise a divorce from Les. Ella tells Joe that Les has told her that barges may cease to be a profitable business in coming years as road transport returns, and that she is indifferent to this after spending her life on the barges. She shares her plans with Joe to divorce Les, and hopefully buy a nice house by Edinburgh to live in with Joe, and Jim, as a family. Joe, an adventurer, pleasure seeker, is unenthusiastic at this. Jim is opently hostile to Joe, and sees him and his mother passionately making love through a slit. Although the physical side of their relationship remains strong, Joe's interest is clearly waning. He continues to receive his salary from Ella, as a salaried barge worker.
When Ella receives word her brother-in-law Sam has died in an accident at work, she and Joe visit her sister Gwen. At Gwen's home, there is an immediate attraction between Gwen and Joe. Ella invites Gwen to spend a couple of weeks with them on the barge, and one evening, on the pretext Gwen would like to see a movie, she and Joe leave the barge and go to a pub. Tho two briefly spend time in the pub, with Gwen seeing that Joe is still carrying a photo of Cathy with him. They finish their drinks, and go to have sex in an alleyway. Upon returning to the barge, Ella soon realises that the two have engaged in sexual activity, and refuses to embrace Joe. Joe goes to a city pub for some drinks, where patrons are speaking about Cathy's case.
In the past, we see that Joe and Cathy had a tempestuous relationship, with Cathy who is working to support the two frustrated by Joe's inability to make any meaningful progress writing his book. The two argue, with Joe throwing custard and other foodstuffs over Cathy, and then, with Cathy crying, covered in various foodstuffs, the two have rough sex, before Joe gets up and leaves, returning later to affectionately embrace the sleeping Cathy.
Joe returns to the barge from the pub, to find Gwen drunk on gin. When Gwen tells him Ella has returned to Les, Joe immediately gets his belongings and leaves. Drinking at a pub, Joe meets a man, Bill, who agrees to take him in as a lodger. Joe immediately begins a loveless affair with the man's wife, Connie, his landlady.
The court case into Cathy's death begins, with Joe attending in the public galleries of the courtroom. He is pleased to hear a friend of Cathy's statement of him having 'gone to China', effectively absolving him of guilt.
In the past, Joe and Cathy tearfully break up outside Cathy's flat, with Joe saying that he is going to China. The two kiss, and Joe takes his things and leaves. Joe throws his typewriter in the canal, spelling the end of his aspirations to be a writer. Meeting each other for the first time, Les sees him doing this, and asks why.
Joe watches Les give his testimony to the court, he also sees Ella there accompanying him, before travelling back to his lodgings by bus. On the way he sees a woman who from behind looks like Cathy, but is not. Upon returning, Joe tells Connie that he believes the accused man is not guilty. Connie tells Joe that they will hang him anyway. The court case proceeds, and it becomes clear that the accused man, Daniel Gordon, will be found guilty.
In the past, we see Cathy's lifeless body floating in the water.
Continuing to attend the court case, which seems certain to result in the conviction of the innocent Daniel Gordon, guilt-stricken Joe writes an anonymous note absolving Daniel of the crime, but not incriminating himself. He leaves the note for a courthouse clerk to find, which he does, but it has no effect on the trial. Joe watches on as Daniel is found guilty by a unanimous jury verdict and sentenced to be hanged. Upset at the conviction of an innocent man, but not willing to risk his own life, Joe takes his things and leaves town, calling in on the spot Cathy fell into the water, throwing the engraved mirror she gave him at the spot she fell and died.
