Mean Girls, 1940

Frenemies, those acquaintances who exchange pleasantries to your face then spit insults behind your back, can be quite vicious. Especially when they’re writers. Old Acquaintance, written by John Van Druten in 1940 and in revival at the Roundabout Theatre Company’s American Airlines Theatre, is an early World War II–era comedic study of the very contemporary frenemy phenomenon.

Kit Markham is a Village-dwelling writer with critical success and bad sales. Her childhood friend, drama queen Milly Drake, churns out best-selling beach reads at a rate to make Danielle Steele blush.

Divorced Milly is green-eyed about Kit’s close relationship with Deirdre, Milly’s bublly teenage daughter, as well as her love affair. One evening, Milly drunkenly reveals some sensitive information to Deirdre about Kit’s love life. The usually calm and collected Kit is not pleased. Catfight!

“In trying to figure out what the play was, that was sort of a pivotal thing,” said Harriet Harris, who plays Milly. “If you’re gonna go over and shake somebody, you’re not slapping them, you’re not yelling at them, you’re not throwing something at them …. Obviously, it has to be comic. You can go in the wrong direction, and I think you lose the really funny, charming, human aspect: why these people are friends and why they’re better people for this friendship.”

Some might remember Ms. Harris as the creepy widow on Six Feet Under who wanted to see her abusive husband’s mutilated body in his casket before he was buried and who later filed suit against the Fishers for emotional damage. She returns to Broadway after her 2002 Tony Award–winning role as Mrs. Meers in Thoroughly Modern Millie.

Ms. Harris said she was delighted to play this Milly. “I think she’s very sweet and very dear, but also someone that is hard to deal with.… [But] at some point, as wonderful as you are, you’re going to have to have some kind of experience where you’re forced to grow up and consider others.”

Kit Markham is played by Margaret Colin, who was last seen in John Patrick Shanley’s Off Broadway play Defiance.

They are directed by Michael Wilson, the current artistic director for the Hartford Stage whom Ms. Harris described as “gentle rather than sarcastic…He took an optimist viewpoint of the play.”

“At first glance, [the play] might seem to somebody like a creaky old chestnut, but it really has very modern things about it,” Ms. Harris said, noting that Milly is a single mother and both of the characters are career women. “These are things that are still surprising, like what it is like to have a lifelong friend. I’m lucky enough to have them. And I’m hoping to keep them.”

Old Acquaintance, Roundabout Theatre Company at the American Airlines Theatre, 227 West 42nd Street. Performances through August 19; www.tickets.com.

Mean Girls, 1940