In the dim light of early morning the township people set out for work (Sad Times, Bad Times). As Pauline, the washerwoman, leaves to deliver a bundle of washing a boy picks out a tune on a penny whistle--the "Little Kong" song, which has become a great favourite with the children. This sets the group reminiscing about the life of King Kong, who has become something of a legend in the township. And so we see the great King Kong in his hey-day, surrounded by photographers, journalists and an excited township crowd (Marvelous Muscles). There's a big fight coming off, and everybody is confident it will be a pushover for the Champ (King Kong). King wins the fight and takes his friends to celebrate in Back of the Moon, the township's most famous shebeen (Kwela Kong).
Joyce, who is the "shebeen queen," falls for King (Back of the Moon). Their love affair goes off at a hot pace, which is unlucky for Petal, who has a secret passion for the prizefighter (The Earth Turns Over). It is also bad news for Lucky, the fast and fancy leader of the Prowlers gang, who had previously been Joyce's man. Later, Lucky and his gang corner Popcorn, King Kong's friend and second, and King and his crowd arrive just in time to save him. In the ensuing brawl, King kills one of the gangsters with his fists, and Lucky swears to get even with him (Damn Him!).
King spends ten months in the cells awaiting trial and Joyce finds new male company. King's trainer, Jack, signs up a new heavyweight, and continues with his pursuit of Nurse Miriam Ngidi. With King out of the picture, the Prowlers have it all their own way in the township. Then one Sunday when the streets are full of people (Gumboot Dance) King Kong returns home acquitted. Everybody is overjoyed to see him and although King's pleasure sours a little when he learns about the new heavyweight, he is reassured by the tribal welcome home given him by the whole township (King King).
Act Two opens with children playing in the township streets. Popcorn warns the children against boxing and tells of trouble in King Kong's camp (Be Smart, Be Wise). Lights go out, the township turns in for the night, then suddenly -- crash! It's another snatch and grab raid by the Prowlers. Things are going badly for King. With Lucky and his gang exerting pressure on any prospective opponents, he can get no proper fights. The best Jack can do is to sign him up with Greb Mabisa, a middleweight. Lucky lets this fight go, knowing it will make a fool of King. Meanwhile, the ex-champ has laid off training, is making no attempt to get fit, and has fallen out with Joyce. But she agrees to give King one more chance, on condition that he never hits another man outside the ring. In the atmosphere of reconciliation, Jack at last announces that he and Nurse Miriam Ngidi are getting married (Quickly in Love).
King loses the fight against Greb. The township is incredulous, and King experiences the scorn and mockery of the early morning bus queue the day after the fight (In the Queue). Lucky and his gang taunt him unmercifully. Enraged, he hits at the people in the queue, and Joyce, in disgust, walks out on him forever.
The whole town comes to Jack and Miriam's wedding (Wedding Hymn) and in the middle of the ceremony King arrives, demanding "Where's Joyce?" A few minutes later Joyce comes in with Lucky, and in that moment King sees not only his own downfall, but Joyce's tragic return to the tough life of the shebeen keeper and gangster's girl. In blind fury, he kills Joyce. At his trial, a showman and eccentric to the end, King dismisses his lawyer, pleads guilty and asks the judge to sentence him to death (Death Song). He is given fifteen years imprisonment, but two weeks later drowns himself in a dam at the farm prison to which he was committed. As the show ends, it is evening in the township yard and the people are streaming back from work.