Richard Crouse

Anyone who has read Bill Carter’s behind-the-scenes-tell-all “The War for Late Night: When Leno Went Early and Television Went Crazy” already knows that the happy, smiling faces you see on your television after midnight aren’t always happy or smiling. That premise is the starting point for “Late Night,” a new comedy written by and starring Mindy Kaling.

Emma Thompson is Katherine Newbury, star of the long-running “Tonight with Katherine Newbury,” a once powerful nighttime chat show. Now the cracks are showing. Ratings are falling off, her all male writing staff are out of touch and worse, the show feels old fashioned compared to the competition. While the Jimmy’s—Kimmel and Fallon—are doing stunts Newbury features Doris Kearns Goodwin, author of “Team of Rivals: The Political Genius of Abraham Lincoln” and signs off with the decidedly unhip, “That’s our show everyone. I hope I earned the privilege of your time.”

Facing cancellation—” The show is a relevant,” says network head honcho Caroline Morton (Amy Ryan). “The ratings reflect that.”—Newbury is pressured into hiring Molly Patel (Kaling), a TV newbie whose only job experience comes from working in Quality Control at a chemical plant. She soon discovers the dangerous chemicals she worked with at the plant have nothing on her new toxic work situation. “You’re hired. If it doesn’t work out, which it probably won’t, you’ll be gone.” The other writers consider her unqualified, a “diversity hire,” and don’t even give her a chair in the writer’s room.

Still, Molly, who honed her comedy chops telling jokes on the loudspeaker at her former job, perseveres. Sitting on an overturned trash can (still no chair) she eagerly suggests ways to make the show better, to make her comedy idol more appealing to a younger audience. “I will not be marginalized by the white fist of oppression that prevails around here,” she says.

Her “never give up” mantra doesn’t play well with the boys’ club, particularly head monologue writer Tom (Reid Scott), but, after a rocky start—”Don’t take this the wrong way,” Newbury says to Molly, “but your earnestness can be very hard to be around.”—the new writer’s spirit gradually wins over the host. “I need you, Molly, to help me change this show.”

Molly may help “shake some dust off the [fictional] show” but “Late Night” doesn’t exactly do a deep clean on its genre. The movie is basically a romcom about platonic female relationships. The plotline may be predictable, never zigging or zagging too far off the straight line starting with Molly’s outsider status and ending with the warm embrace of those who once shunned her, but sharp writing and engaging performances from Kaling, Thompson and John Lithgow as Newbury’s ailing husband, keep it on track.

It is a showcase for Thompson’s ability to elevate any movie she appears in—she puts a nice spin on Newbury’s “The Devil Wears Prada” persona—and for Kaling’s sensibility both as a writer and performer. Together they guarantee “Late Night” is more than a “Working Girl” update.