Neil Simon probably can't win for losing. When "California Suite" opened 19 years ago, Variety remarked that his recent work had been too dark and welcomed him back to top form with a quartet of plays that expertly underscored the gag humor with some serious themes. Talk about a cyclical career: Has anyone come full circle as many times as Neil Simon?

Neil Simon probably can’t win for losing. When “California Suite” opened 19 years ago, Variety remarked that his recent work had been too dark and welcomed him back to top form with a quartet of plays that expertly underscored the gag humor with some serious themes. Talk about a cyclical career: Has anyone come full circle as many times as Neil Simon?

In “Laughter on the 23rd Floor,” Simon paid affectionate tribute to his years as a sketch writer for Sid Caesar, a play that persuasively captured both the lunatic air of TV’s golden age and the sinister national paranoia that had infiltrated the entertainment industry during that same period.

It had a difficult Broadway run nonetheless, which is certainly a key reason for Simon’s move to the less familiar confines of an Off Broadway theater.

Simon’s failures have always been at least as interesting as his successes, because the ones that disappoint — and “London Suite” unquestionably falls in that category — often do so because he’s turned off the autopilot and veered into unknown territory.

Approaching 70, Simon is still trying to figure out what funny means in a business that’s wildly different from the one he ruled for two decades as king of the Broadway comedy.

Set in John Lee Beatty’s irresistibly inviting homage to the Connaught Hotel, “London Suite” follows the format of “Plaza Suite” and “California Suite,” even reuniting one couple from the latter.

It finds the playwright again wrestling with the elements of comedy, but this time his alchemy is imperfect.

Indeed, the first half is leaden, and the second, while far more interesting, still yields only the occasional flash of brilliance. A long run is doubtful.

In “Settling Accounts,” a once successful, now washed-up writer (Jeffrey Jones) confronts the sniveling financial manager (Paxton Whitehead) who has stolen his life’s savings.

In “Going Home,” a widow (Carole Shelley) recounts the disastrous date, arranged by her daughter (Kate Burton), with a wheezing, twitching, snorting, coughing Scotsman.

Notwithstanding the gun-waving in the former and the modest revelation in the latter, both playlets lack any real payoff: Promising showdowns that never materialize, they just sort of drift off into the ether.

“Diana and Sidney” increases the stakes considerably.

In “California Suite,” they were a barely married British couple in town because she was an Oscar nominee.

The present finds them long divorced, Sidney (Whitehead, in the evening’s most restrained and thoughtful performance) having spent the last six years living with his male lover on Mykonos, and Diana (Shelley, also shown here to her best advantage) about to begin her ninth season as the star of a successful TV series.

What begins as a nervous reunion turns darker as an illness is exposed and the couple rehash what they have and have not meant to one another across a quarter of a century.

The two most striking things about “Diana and Sidney” are Simon’s attempt to draw a gay man, and his inability to make either of these characters credible (which doesn’t, by the way, prevent them from touching us, at least a bit).

With Sidney, he falls into a trap he more typically does with women, which is to idealize the unfamiliar.

Despite his tan, Sidney’s so dreamily ethereal he seems on the verge of vaporizing before our eyes.

He hopes Diana will support him in his last months so that he might learn to paint, which leads one to wonder just what the hell he’s been doing for the last six years (with a lover who’s supposed to be a sculptor, no less).

For her part, Diana is knocking back double vodkas for breakfast and can’t pull herself together for lunch despite the fact that she’s clearly got the upper hand in this failed relationship, at least financially, which proves to be considerably important.

In the end, Sidney and Diana conjure up a vision of those final months that’s meant to evoke Oscar Wilde, but nothing nearly so dangerous — nor, with its tired cracks at British musicals, remotely as witty — emerges.

With “The Man on the Floor,” Simon at least sends the audience out laughing — laughs having been in remarkably short supply until now — with a bit of slapstick about an American couple in town for Wimbledon that allows Jones to do an amusing catalogue of barks and grimaces as a man who throws his back out.

Simon knows a thing or two about bad backs — and about the intangibles of creativity described by both of the other leading men in “London Suite.”

Daniel Sullivan’s staging is never better than proficient, and Burton is consistently awful in every role (she also has to endure a gag about her father that you see coming a mile away).

But that gorgeous set, nicely lit by Ken Billington, and Jane Greenwood’s lovely clothes, are all spot-on.

Going Off Broadway, Simon made a statement about reducing the financial risk in getting a play on. But unlike some of his missteps, “London Suite” represents a reduced artistic risk as well.

Certainly, he’s earned the right.

But where comedy counts, the standards he falls short of tend to be his own.

London Suite

Union Square Theater, New York; 499 seats; $40 top

Production

An Emanuel Azenberg and Leonard Soloway presentation of four one-act plays (one intermission) by Neil Simon. Directed by Daniel Sullivan.

Creative

Set, John Lee Beatty; costumes, Jane Greenwood; lighting, Ken Billington; sound, Tom Clark; wigs, hair, Paul Huntley; casting, Jay Binder; associate producer, Ginger Montel; production stage manager, John Vivian. Opened April 9, 1995, reviewed April 6. Running time: 2 hours, 10 min.

Cast

SETTLING ACCOUNTS: Jeffrey Jones (Brian), Paxton Whitehead (Billy).
GOING HOME: Kate Burton (Lauren), Carole Shelley (Mrs. Semple).
DIANA & SIDNEY: Carole Shelley (Diana), Kate Burton (Grace), Paxton Whitehead (Sidney).
THE MAN ON THE FLOOR: Jeffrey Jones (Mark), Kate Burton (Annie), Carole Shelley (Mrs. Sitgood), Brooks Ashmanskas (Bellman), Paxton Whitehead (Sr. McMerlin).
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