Based on the novel by Guillaume van der Stighelen, a story about love, family and urinals. The young Guillaume Van der Stighelen finds "the siphon", a revolutionary invention. When his great childhood love drops him for a rich good-for-nothing, he marries another woman and decides to build a plumbing empire. The business becomes a success and Guillaume makes a fortune. His wife becomes his great support and refuge, 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 succeeded during and after the war in saving his company and further expanding it. At the insistence of his wife, he has since handed over the business to his sons. But at what cost?
The theater text Rozeke is based on the novel of the same name written by the great-grandson of plumbing tycoon Guillaume Van der Stighelen, namely former advertising man and author Guillaume Van der Stighelen.