Few directors grasp the silent storms inside average Americans better than Richard Linklater, the visionary behind “Everybody Wants Some!!” and “Boyhood.” His latest film, “Last Flag Flying,” is a sort-of sequel to Darryl Ponicsan’s novel and film “The Last Detail,” about three pals who meet while serving in the Navy and Marines during the Vietnam War.

Although the characters here are the same, the circumstances are quite different — most notably, the boosted seriousness of a crime they committed for which one pal served brig time.

Set in 2003, “Flag” reunites buddies Doc (Steve Carell), Mueller (Laurence Fishburne) and Sal (Bryan Cranston) as they drive from Virginia to New Hampshire to bury Doc’s son, a Marine who died serving in Iraq. Yes, it’s a gloomy premise for a road-trip movie, but life-affirming, too. Like an Irish wake, the tone is somber, morbid and funny.

Especially thought-provoking here is the trio’s love-hate relationship with the armed forces. On one hand, being in uniform gave them the best years of their lives. On the other, they’re all ashamed of what they did and unsatisfied with where they are today.

All three actors are terrific.

No one can instantly command an audience’s sympathy like Steve Carell can. He’s America’s poet laureate. Once an “Office” clown, now he’s a fixture of dramas, and his style of acting — reserved and lonely — resonates powerfully with viewers. You might find yourself waiting for Carell’s character to sob or break down — that’s what people do in movies, right? — but Carell never gives in to that easy impulse.

Breaking the tension is Fishburne, whose Mueller has become a preacher, as he balances his new holy life with his cussin’ and boozin’ past. And there’s also Cranston’s Sal, a dive-bar owner, who is nearly too outsize for this intimate movie. But his role as a jovial alcoholic, all too familiar, really drives home the lifelong reverberations of war.

The song that rolls at the end credits is Bob Dylan’s “Not Dark Yet.” It’s a perfect coda for Linklater’s movie — it mimics the steady pulse of “Flag,” its warmth and Doc’s cautious optimism in the face of personal tragedy.

“It’s not dark yet, but it’s getting there.”