“It/I” is a two-character theater play in which the human character I (played by a real actor) is taunted and played with by an autonomous computer character It on a computer-controlled, camera-monitored stage. The play, performed before live audiences in November 1997, brought an automatic computer character to a theatrical stage for the first time ever. This paper reports the experience and examines important technical developments needed for the successful production of “It/I”. In particular we describe the interval script paradigm used to program the computer character and the ACTSCRIPT language for communication of actions and goals. Although our experiments have been restricted to physical interactive spaces, we believe that interval scripts and ACTSCRIPT can successfully address the control and management of any virtual environment with a complex temporal structure or a strong underlying narrative.