Tucci both directs and co-stars (with Ian Holm below) as joe Mitchell, the staff writer on The New Yorker who first made Joe Gould famous.

Gould was scarcely a romantic figure. He was, according to Tucci's and Howard Rodman's screenplay, "about five foot four, bald on top with scraggly hair in the sides and back. He has an unkempt beard and yellow teeth. His face is greenish grey, the right side of his mouth twitches and his eyes are bloodshot. He wears loose, lop-sided glasses that keep slipping down his nose. He wears a dirty seersucker suit, a frayed and dirty Brooks Brothers button-down shirt, a filthy mismatching tie and dirty sneakers." To this, Holm has added a beret, that trademark of the bohemian movement.

Though he can scarcely remember them, the Joe Gould Mitchell describes has seen better days: the son of a doctor from a Boston family "who have been the Goulds since the Cabots and the Lowells were clam-diggers", he studied at Harvard. Then, defying his father's wishes, he headed off to do "a variety of unsuitable things", including measuring the heads of Chippewa Indians on a reservation in South Dakota and working as a messenger boy-cum-police reporter on a New York newspaper. Finally, however, inspired by a phrase of Yeats', he hit on what was to become his life's work: an Oral History of the United States. It was a huge work, possibly partly imaginary, sections of which he stored with friends around the city - and, in one spectacular miscalculation, in the basement of a Long Island farm which no one ever seems to have been able to find after his death.

We meet Gould through Mitchell, who spots him in a diner, is intrigued and tracks him down. Gould, sensing a few free meals, is scarcely elusive. But what develops is a bizarre friendship, with Gould telling Mitchell about the 'Oral History' - an attempt to record the lives of the ordinary people of America in their own words - and Mitchell, in return, making Gould briefly famous through a profile in The New Yorker.

From that point on, the bohemian latches onto Mitchell, taking him in tow as he gatecrashes literary soirees, introducing him to his artist friends, bombarding him with anecdotes and epithets, and calling him at all hours of the day and night. In the end, Mitchell steps back from the relationship and, in a moment of anger, implies that Gould is content to play the role of the writer whose work has been rejected by publishers, and that it is laziness on his part rather than the refusal of others to recognise his genius that has prevented the publication of the 'Oral History'. Gould never forgives him. What is more, the crisis between the two Joes becomes the start of Professor Seagull's decline. But, reckons Tucci, Mitchell and Gould were more alike than either would ever have admitted.

"I think Gould was a very irritating man," he concedes, "and Mitchell quickly became exasperated. I think the audience will certainly have similar feelings, though whether it's irritation or exasperation, I'm not sure. But I think they will definitely see the similarities between the two men."