Camera Obscura, The Almeida Rehearsal Room, London

In bed with Arthur Inman

The tables have been turned on the excellent actor Peter Eyre. Earlier this year, as Kenneth Tynan paying court to Louise Brooks in Smoking with Lulu, he played the visitor of a legendary recluse. Now, in Lorenzo DeStefano's fascinating play Camera Obscura, he plays the legendary recluse who is being visited, skilfully switching from bedside to in-bed manner.

The show is based on the real-life diaries of Arthur Crew Inman (1895-1963), a moneyed American who made a kind of art form of his phobias (to light, noise, John F Kennedy etc) and took the principle of room service to quite extraordinary lengths. Unwilling to leave his darkened apartment in the Garrison Hall hotel, in Boston, where he had bought all the neighbouring flats in a doomed effort to eliminate disturbance, he advertised in the press for "talkers" to tell him the story of their life. Some of the females who responded were fondled; others had full sex. The diaries therefore became an informal and unpublished Kinsey report avant la lettre. His live-in wife put up with his behaviour.

The photo of a testy-looking, toothbrush-moustached Inman in the programme suggests a peppery, wired-up individual. Eschewing impersonation, Peter Eyre converts the character into a great tragicomic creation, his demeanour reminding you more of the flabby Wilde, and his seductively low-key Southern drawl, of a Tennessee Williams faded belle. The dimpling, little-boy bids for pathos are as outrageously manipulative as his innocent-seeming curiosity when he's pruriently quizzing his lady visitors about the precise sensations felt during the female orgasm. There's something at once floppily invertebrate and strong-willed about this whisky-swigging, politically bigoted self-made invalid who takes such a calculatedly childish delight in tape-recording every embarrassing session. To be goosed by him would be like being molested by a tenacious blancmange.

Yet the play and the performance help you to see why so many people remained loyal to him – not least his wife, whose oscillation between exasperated affection and the desperate desire for some freedom and dignity is beautifully captured by Diana Hardcastle. The hypochondriac's gently insistent air of total entitlement would very quickly, you feel, enslave anyone without his paradoxical strength of character. But that manner covers a terrible pathos.

The play is shaped in the life-in-the-day-of format, and it happens to be the day, in 1963, on which he took his own life. The consequences of his warped manner of existence crowd in on him. Through a succession of encounters, which the expert shading of Jonathan Miller's production prevents from ever feeling like a desultory straggle of visits, Inman makes some painful discoveries. He forces his wife into revealing her 30-year affair with his doctor and friend, Cyrus Pike (Jeff Harding). His sinister, Orton-esque Dutch manservant (Richard Brake) turns out to have passed on one of the incriminating diaries to his landlords, raising the threat of eviction from his cocooned redoubt. And not just the living come to pay their disrespects. Causing him to curl up in a foetal heap, his cotton-baron father pops back from the dead to remind Inman of his vain attempts to become a poet, derisively quoting the awful doggerel and its vicious reviews.

And yet this failed artist, this Proust without the excuse of a great novel, left a vast literary legacy: 17 million words in 155 volumes of diaries. It can only be a compliment to the play, production and cast that they have left me avid to get hold of the published extracts.

To 8 June (020-7359 4404)