Once in the filmmaking mindset, and having written teleplays before, Michael Crichton also went for wrtigin screenplays, beginning with Extreme Close-up (1973), also known as Sex Through a Window, and one of his most famous screenplays, Westworld (1973). In 1978 two further screenplays were made into films by himself, with Coma, based on Robin Cook's novel, and The First Great Train Robbery, which is the only one which he wrote, directed and was based on one of his own novels. Later he again directed himself his own screenplays for Looker (1981) and Runaway (1984).
In 1996 he co-wrote the screenplay for Twister with his then wife Anne-Marie Martin, whom he had met on the set of Runaway.
Anne-Marie Martin, on the set of Runaway