It begins with an act of auto-erotic asphyxiation in a cocked hat and tutu. It continues with a full-size, working crucifix in an English stately home, and ends in a moribund House of Lords, where one speaker’s skeletal hand drops off. It contains outbursts of gibberish, Tourettian filth, a bit of unicycling and snatches of musical numbers from the “Internationale” to “Dem Bones”, as well as at least one grisly murder and a struggle between two nutters each of whom claims to be God. Ah, Peter Barnes is back in the West End.
    
In Barnes’ breakthrough play, the newly ennobled 14th Earl of Gurney panics his patrician family by claiming to be the New Testament God of love. Later, apparently cured of this delusion and answering to his given name of Jack, he sees off manipulative relatives but also now secretly identifies with an altogether darker figure: another Jack, from the 1880s.
    
Barnes’ technique was to mix comedy and cruelty as provocatively as he could in an attempt to stir audiences up. His target here is openly announced in the title, and 47 years after its première, it has once again become topical thanks to the resurgence in Britain of class privilege. Given the educational background of much of the current inner governmental circle, it draws blood when Jack Gurney is finally declared sane by dint of engaging his examining doctor in an energetic rendition of the Eton boating song.
    
James McAvoy returns for a second season to director Jamie Lloyd’s Trafalgar presentations. His Jack Gurney is by turns charming (with just a touch of Peter O’Toole in the 1972 film version) and even more chilling than his Macbeth here last season; his smile can charm you across a flowery meadow or make you resolve never to risk walking down a darkened alley with him. He receives strong support from Ron Cook as a spluttering uncle, the underrated Anthony O’Donnell as a drunken, revolutionary butler and Forbes Masson in a clutch of roles from a Women’s Institute officer to “the electric Christ”. In this confusing-by-design, jump-cut age of ours, Barnes may finally have come into his own.
    
Written for the Financial Times.