Fun Begins as ‘Doctor’ Becomes Truly Nasty : Theater review: Stick around for the second act to learn just how mean the characters can get in Sondheim and Furth’s new comedy-thriller.

At the end of Act I of “The Doctor Is Out,” the nasty new thriller by Stephen Sondheim and George Furth having its world premiere at the Old Globe Theatre, only one question remains. Why come back for the second act?

My question, however, may not be what it seems. “The Doctor” is written with a nod to the grand tradition of “And Then There Were None” and “Diabolique,” with a little “Dallas” thrown in. But the murder has been effectively solved and the fate of every character seemingly wrapped up with absolute finality by the end of Act I. The second act is not so much a whodunit it as a just-how-nasty-can-these-people-get?

And this group is pretty nasty. They are seven extremely disparate New Yorkers, members of a group therapy, who have gathered in the apartment of their psychiatrist, only to find that the doctor is really out--he’s lying murdered in the adjoining room.

Because of some arcane details of Manhattan high-rise living--a sign-in sheet in the lobby, a limited supply of elevator keys--the patients decide that the murderer must be among them. They proceed to play detective, with the audience right behind, examining every detail of each character’s afternoon and neurosis for the key to the murderer’s identity. Nevermind if one or another is caught in a lie; everyone’s guilty of something here.

The suspects are: Martin Chisholm, played with devilish cool by John Rubinstein, a powerful media consultant so savvy he is practically running the city; Dossie (Becky Ann Baker), a blowzy nymphomaniac; Pamela (a refreshingly crisp Kandis Chappell), one of those glamorous, incredibly bitchy, unbelievably sarcastic Manhattan women; Dan (Chuck Cooper), an embattled ex-police detective; Nam-Jun (Takayo Fischer), a whiny, bitter academic; Vassili (Josh Mostel), a slovenly Greek emigre passionately devoted to baklava, and Gregory (Terrence Mann, looking swank now that he’s freed from his “Beauty and the Beast” makeup), a real estate tycoon with the ethics of the shark from “Jaws.”

Why, even the dead doctor (F.J. O’Neil) is revealed to be a true son of a bitch. That’s why the second act is in fact more fun than the first. Because that’s when things get really nasty, breathtakingly nasty, apocalyptically nasty. And the fun is in the nastiness, not in the guessing, despite Sondheim’s reputation for making up hard-to-figure-out games.

Although this is his first ever non-musical play, “The Doctor” is not exactly a departure for the great composer/lyricist. He’s played with the form once before, in the 1973 film mystery “The Last of Sheila,” co-written with Anthony Perkins. In fact, brittle, arch and even euphorically evil characters populate the Sondheim musical landscape, from “Follies” to “Sweeney Todd” to “Assassins.” In “The Doctor,” the wry Manhattan banter of some of the characters resembles the zingers tossed about in “Company,” the landmark 1970 musical, with a book by Furth. This time, though, the writers revel in the fun of not having to care about anyone they’ve created.

Not everything pays off, however. The smart, funny lines are sprinkled throughout a little too thinly. Some of the running gags on the character’s neurosis--particularly in the case of the jealous academic, Nam-Jun--are repeated endlessly without getting any funnier. A subplot involving a Jennifer Levin-like murder in Central Park seems stretched and given a lot of stage time for its nominal importance in the plot. Also, director Jack O’Brien cross-cuts, not always smoothly, between the subplot and the main plot using the loudest moments in a thunderstorm to interrupt the action.

And because of the precision of the plot and because Sondheim is practically a lifelong Manhattanite, several not-credible details of crucial importance to the mystery nag. Where exactly on the Upper West Side of Manhattan does everything shut down at 6 p.m.? What dilapidated apartment building has a mandatory sign-in sheet in the lobby, and what kind of psychiatrist distributes elevator keys to his patients?

The story unfolds on a dark and rainy evening. Douglas W. Schmidt (set) and Kenneth Posner (lights) have created a spooky old apartment building whose former grandeur can be spied through the glass ceiling, where part of the facade peeks through. The designers have also created an impressively real and very elegant steamy rainfall against an evening sky.

In the end “The Doctor Is Out” is a thriller that enjoys riffing on the old adage that absolute power corrupts absolutely. The play, conversely, entertains, but not absolutely.

* “The Doctor Is Out: A Comedy Thriller,” Old Globe Theatre, Balboa Park, San Diego, Tue.-Sun., 8 p.m.; Sat.-Sun., 2 p.m. Ends Oct. 21. $20-$36. (619) 239-2255. Running time: 2 hours, 30 minutes.

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

John Rubinstein: Martin Chisholm

Becky Ann Baker: Dorothea (Dossie) Lustig

William Ragsdale: Young Man

Elisa Llamido and Nestor G. Carbonell: Couple in bar

Crystal Allen: Charmaine

Kandis Chappell Pamela Prideaux

Josh Mostel: Vassili Laimorgos

Terrence Mann: Gregory Reed

Chuck Cooper: Dan Gerard

Takayo Fischer: Nam-Jun Vuong

Nestor G. Carbonell: Roberto

F.J. O’Neil: Dr. Conrad Bering

An Old Globe Theatre production. By Stephen Sondheim and George Furth. Directed by Jack O’Brien. Sets Douglas W. Schmidt. Costumes Robert Wojewodski. Lights Kenneth Posner. Sound Jeff Ladman. Fight director Steve Rankin. Stage manager Peter Van Dyke.