Portrait of a man of many parts

"His show deeply impressed me," Berkoff recalls. "Not only its skill and audacity, but the ability to bring all those aspects of acting together to serve his purpose in creating this extraordinary drama-documentary on Kean. It was inventive, imaginative and dynamic."

O'Loughlin recalls the encounter. "He came to my show. I got halfway round the audience and found him in the middle of one of the rows. The audience was looking at him, not me. So I gave the first speech to him."

The complete trilogy (which O'Loughlin describes as "pursuing a line of investigation in theatre that combines physical and classical theatre") will be presented at this year's Fringe, with the third and final part of the story receiving its world premiere. O'Loughlin plays all of the characters in the life of the actor who made Shakespearean roles his own, particularly that of Richard III, but whose private life was marred by scandal and bouts of heavy drinking.

"Edmund Kean is a hero figure of the British theatre from whom young, struggling actors often take nourishment," Berkoff says. "Like boxers and dancers, we choose a person who, by reflection, if you like, gives us a status and to whom we can look for encouragement in frailer and weaker moments."

So, what exactly does the job of mentor involve? "I keep an eye on him," says Berkoff, simply, revealing that he would have been grateful for a mentor during his own early career. "I would have liked there to have been somebody I could to go to and pour out my own longings and frustrations to," he says. "But I have had to deal with it all by myself."

5 to 28 August at 4.30pm (0131-667 2212)