It’s not just the box office bonanza casting of Ian McKellen and Patrick Stewart as 20th century art’s most celebrated tramps that makes this latest revival of “Waiting for Godot” unusually theatrical. But adding overt theatricality is not the same as realizing the still-powerful ideas coursing through this allegedly undramatic drama.

Helmer Sean Mathias and designer Stephen Brimson Lewis obey the playwright’s instruction of presenting a bald tree that — in a rare suggestion of color and hope — sprouts leaves for the second act. But their tree has burst through the floor of a theater.

This stage-within-a-stage, with splintered, faded boards, torn walls and empty boxes on either side, has a fashionably post-apocalyptic air, its dusty rubble not a million miles from Deborah Warner’s recent National Theater revival of Beckett’s later “Happy Days.”

Determined to push the metaphors still further, Mathias adds sound effects ranging from comic (a cartoonish “boiiiiiing” when Pozzo’s stool is sat upon) to atmospheric (wind effects to conjure a barren landscape).

Into this world clambers McKellen’s soulful, put-upon Estragon. Round-shouldered and shambling, his huge hands describing the air like birds, McKellen flits from grumpy to gleeful in a blink of piercing blue eyes. With McKellen baleful as a basset hound, his clownlike handling of silence makes Estragon’s childlike neediness immensely touching.

This is an actor who can — and does — make a meal out of munching a carrot, beneath the long-suffering gaze of Stewart’s more peremptory Vladimir. That performance is altogether more contained, physically and vocally. He is the more responsible of the pair, looking after his foundering companion after 50 years of friendship.

There is, however, a nagging lack of consistency to their portrayals. Mathias ups the ante on the vaudevillian shtick, and both actors knock out nifty footwork when the fancy takes them. But although it would be foolish to expect naturalism in “Waiting for Godot,” how come so doddery an Estragon, incapable of taking off his own boots, can so nimbly cut capers? And given that both actors are exactly the right ages for the roles, why are they consciously acting older? The effect is to keep themselves — and the audience — at a remove from the characters.

Beyond their individual work, the too evenly paced production suffers from an unwelcome strenuousness; it runs a full 25 minutes longer than the current Broadway revival. It’s as if each moment has been considered, but underlying rhythms and shapes have been ignored.

The major victims are the Pozzo and Lucky scenes. Simon Callow’s puffed-up, permanently red-faced Pozzo bellows like a circus ringmaster. But unmodulated fury is inexpressive. Ronald Pickup’s dignified Lucky also suffers from directorial overkill. Mathias allows the other characters to yawn and be ostentatiously bored in his monologue, which only encourages audiences to stop listening.

In the more successful second act, Vladimir takes pity on his sleeping chum Estragon, removes his own jacket and places it across his lap. Waking with a lurch, Estragon shoots his hands into the sleeves and finds himself accidentally straitjacketed and terrified. As Vladimir soothes him, their tender interdependency is made flesh. Touching though that is, there’s more to “Waiting for Godot” than a double-act.

Waiting for Godot

Theater Royal Haymarket, London; 895 seats; £47.50 $71 top

  • Production: A Theater Royal Haymarket Company presentation, in partnership with Duncan C. Weldon Prods., of a play in two acts by Samuel Beckett. Directed by Sean Mathias.
  • Crew: Sets and costumes, Stephen Brimson Lewis; lighting, Paul Pyant; sound, Paul Groothuis; production stage manager, Patrick Molony. Opened, reviewed May 6, 2009. Running time: 2 HOURS, 35 MIN.
  • Cast: Estragon - Ian McKellen Vladimir - Patrick Stewart Pozzo - Simon Callow Lucky - Ronald Pickup Boy - Tom Barker/Richard Linnell/ George Sear/Sam Walton
  • Music By: