The young Guillaume Van der Stighelen finds 'the siphon', a revolutionary invention. When his great childhood love leaves him for a rich good-for-nothing, he marries another woman and decides to build a plumbing empire. The company becomes a success and Guillaume makes a fortune. His wife becomes his great support and confidante, his little daughter Rozeke the apple of his eye, but the relationship with his three sons becomes increasingly strained. Then Guillaume sees his childhood love again. On his 88th birthday, the old Guillaume looks back on his life. He is proud that he managed to save and further expand his company during and after the war. At his wife's insistence, he has since handed over the business to his sons. But at what cost?...