In Adelaide, the wife of Dr. Brian Cowper, Jill Cowper, is writing her thesis at home for her Master's in Anthropology. When the plumber, Max, arrives unexpectedly to do a routine check and maintenance of the the bathroom pipes, Jill is stuck alone at home with the strange, talkative stranger. That day, he mentions spending some time in prison, frightening Jill. She talks about this to her friend Meg, her husband Brian and the superintendent's wife, but they all believe the plumber to be a simple, but nice man. Jill does not agree. There is a problem in the bathroom that brings Max back again, this time even longer. Over time, the tension between them increases. Finally, Jill finds a way to get rid of the plumber.