An Oak Tree. This takes its name from Michael Craig-Martin's 1973 work An Oak Tree in which the artist asks us to suppose that a glass of water has become a tree. Crouch's play shows us an encounter between a stage hypnotist and a grieving father, Andy, whose daughter has been run over and killed by the hypnotist. The father, who believes that he has transformed a tree into his dead daughter, comes to see the hypnotist hoping that he can provide some answers.