Mental breakdowns. Dead children. The irreversible ravages of time. Loss is never far away in “The Trip to Bountiful,” Horton Foote’s masterful 1953 play. Mr. Foote’s works have a reputation for being wistful and deliberately paced. They are, but he has an unheralded gift for showing the jagged emotions pulsing within even the most pedestrian lives. The Signature Theatre’s heartfelt but oddly tentative revival, starring Lois Smith as Mrs. Carrie Watts, gives voice to these impulses as well as the more familiar ones that have branded Mr. Foote our reigning theatrical humanist.

Mrs. Watts has spent 20 miserable years living with her depressive son, Ludie (an appropriately passive Devon Abner), and her shrewish daughter-in-law, Jessie Mae (Hallie Foote, Horton’s daughter and frequent collaborator), in a tiny Houston apartment. Mrs. Watts is 60, her heart isn’t in the best shape, and she wants to return to her tiny hometown of Bountiful before she dies. Ludie and Jessie Mae want her to stay. She finally goes, and they head after her.

That’s it. That’s the plot of “The Trip to Bountiful.” But Mr. Foote supplies Mrs. Watts with enough memories and regrets, enough obstinacy and wisdom and serenity, to turn this straightforward story into something almost unheard of these days: a work that makes virtue as compelling to watch as vice.

Perhaps because this sentiment is so antithetical to the current pop-culture mood, the play takes a while to put down roots. Its delicately shaded emotions have a smudged quality in Harris Yulin’s hands early on: One confrontation between Mrs. Watts and Jessie Mae over a recipe seems particularly under-rehearsed. And not even Ms. Foote’s preternatural skill at interpreting her father’s work can give the self-centered, carping Jessie Mae the range of emotions that Ludie and Mrs. Watts both have. (Mercy, she doesn’t even like the sound of hymn singing!)

But once Mrs. Watts gets out of that apartment and starts moving, so does the production. The ensuing bus ride, punctuated by a few stops, provides the play with its emotional spine. Mrs. Watts suffers the occasional setback but soldiers on with the help of her newfound traveling companion, a pretty war bride named Thelma (Meghan Andrews). Along the way, Mrs. Watts alludes to the two children she buried in Bountiful, the man she loved but didn’t marry, the man she married but didn’t love, and the God who has offered sustenance along the way: “I wonder why the Lord isn’t with us every day? It would be so nice if He was. Well, maybe then we appreciate so much the days when He’s on our side.”

With her firm gaze and solid arms, Ms. Smith, a veteran of Chicago’s rough-and-tumble Steppenwolf Theatre, is much sturdier than either Lillian Gish (who created the role first in a teleplay and then on Broadway) or Geraldine Page (whose performance in the 1985 film version is just shy of perfection). The odds of this Mrs. Watts not reaching Bountiful are about as good as the odds of Ma Joad – another part played by Ms. Smith – giving up on the way to California in “The Grapes of Wrath.”

This has an odd effect on the play. The early confrontations between her and Jessie Mae feel like a fairer fight, and it’s easy to see why the ineffectual Ludie never blossomed underneath her. But some of the play’s kindnesses feel extraneous when offered to someone this indomitable. “When you’ve lived longer than your house or your family,” Mrs. Watts says after one change of fortune, “maybe you’ve lived too long.” This time around, you really don’t get the sense that she means it.

Nonetheless, her trip ends – as any trip must after 20 years of anticipation – with at least a few stabs of disappointment. But even Mr. Foote’s deepest moments of melancholy are leavened with the odd reminder of grace. Bountiful could never possibly live up to Mrs. Watts’s mental image of it, but the sight and sound of its birds (aided by Brett Jarvis’s sound design) come close. She and a kind sheriff (Jim Demarse) mention almost a dozen different types in a discussion that concludes:

Mrs. Watts: I guess a mockin’ bird is my favorite of them all.

Sheriff: I guess it’s mine, too.

Mrs. Watts: I don’t know, though. I’m mighty partial to a scissor tail. I hope I get to see one soon.

Sheriff: I hope you can.

“I hope you can.” The line does nothing to push the plot of “The Trip to Bountiful” forward, yet there it is. And there it ought to be. Many people – I like to think most – would have seen this spirited but failing old woman and thought something close to that phrase. Rare are those who would actually say it and, however briefly, turn a pleasant chat into a benediction. For almost 65 rich years, Horton Foote has turned his attentions toward those people. Even in this hesitant and at times cloudy production, he reminds us what marvelous company these surprisingly tormented, dependably decent men and women can be.

Until January 8 (555 W. 42nd Street, between Tenth and Eleventh Avenues, 212-244-7529).