For millennials, at least, “Desk Set” features a plot so outdated that it could have been subject to government recall.

Audiences willing to accept the time in which it was written, however will find a bright and witty comedy — perhaps the most underrated of the Katharine Hepburn-Spencer Tracy vehicles.

The 1957 film will be shown Saturday and Sunday at Hoquiam’s 7th St. Theatre as part of its Silver Screen Classic series.

Tracy plays Richard Sumner, an efficiency expert hired to modernize the operations of a television network through the installation of computers. His presence naturally arouses the suspicions of Bunny Watson (Hepburn), the head of the network’s research department.

Although Bunny and her co-workers can recite Ty Cobb’s baseball statistics and the Longfellow poem, The Song of Hiawatha, from memory, she fears that computers will make her all-female staff obsolete.

Most companies today, of course, would have long since jettisoned the women in favor of technology — most issuing the heartwarming statement that the layoffs better suited the company’s business strategy moving forward.

In this case, though, Sumner takes his time observing the research department’s operations. In the process, he becomes interested in Bunny — and in breaking up her long relationship with a slow-to-commit network executive played by Gig Young.

In the eighth of their nine films together, the 57-year-old Tracy and 48-year-old Hepburn were getting a trifle old for conventional romantic comedy. It was probably wise, therefore, that screenwriters Phoebe and Henry Ephron (the parents of “Sleepless in Seattle” writer-director Nora Ephron) and director Walter Lang refrained from staging explicit love scenes.

But the chemistry of the co-stars, longtime partners both on and off the screen, remains as sharp as ever. Tracy, who once famously contended that his secret of acting was to never let the audience catch him acting, characteristically underplays brilliantly. Hepburn is perfectly cast as an intelligent professional who is more brittle emotionally.

Curiously, the human vs. technology angle is somewhat underdeveloped until the final 30 minutes. Viewers accustomed to smartphones and tablets might be amused to discover that the computers, once they arrive, are about the size of a meat locker.

The film’s strength is the verbal sparring between the co-stars and Young, himself a gifted comedic actor. The movie isn’t always outrageously funny, but it’s always fun to watch.

One unintentionally humorous element is the casting of Dina Merrill as one of researchers fearful about hitting the unemployment line. In reality, Merrill (the heiress to the Post Cereal fortune) was wealthy enough to preserve her job by buying the network.

That might have made for an interesting comedy in itself, but probably not as enjoyable as “Desk Set.”