“Shipwreck,” the second installment in Tom Stoppard’s sprawling “Coast of Utopia” trilogy, takes place between 1846 and 1852, when its protagonists — a group of Russian intellectuals that includes the self-questioning Alexander Herzen (Brían F. O’Byrne) and the author Ivan Turgenev (a fine Jason Butler Harner) — were whiling away their time in Europe, earning themselves the title of “superfluous men.” Not the most promising period from a dramatic perspective, even with the abortive French revolution of 1848 tossed in.

On top of this, the middle part of any trilogy always suffers from an identity crisis. By saving any major plot resolutions for the third and final part, it forces an arbitrary and unfulfilling caesura onto the narrative. From “Henry VI” to “Lord of the Rings,” the second time is rarely the charm.

Does it sound like I’m making excuses for “Shipwreck”? Well, I guess I am. Mr. Stoppard spends down some of the considerable theatrical capital he accumulated with “Voyage,” the trilogy’s masterful first entry. Too many arguments among Herzen and his philosophical brethren devolve into comic squabbles, and Mr. Stoppard falls prey to some uncharacteristically lumpy exposition: “Something’s wrong this year,” complains Herzen’s wife, Natalie (Jennifer Ehle), “even though it’s all the same people who were so happy together when we took the house last summer.”

And Jack O’Brien’s staging, so crisp in “Voyage,” overcompensates here with a glut of visual pictures that are ravishing but of questionable import. Particularly in the first hour of “Shipwreck,” the trilogy’s projected nine-hour running time feels less like a promise and more like a threat.

If anyone could maintain the intellectual fervor and logistical prowess required for this staggering undertaking, it’s Mr. Stoppard, who has mined enticing drama from the second law of thermodynamics (“Arcadia”) and Zeno’s paradox (“Jumpers”). He did it again with “Voyage,” a gutsy, rapturous blend of political debate and heartbreak that followed the previous decade in the lives of these tsarist agitators. (“Voyage” is still being performed in repertory; the third part, “Salvage,” joins the others in February.) And he has once again picked up the thread by the time “Shipwreck” reaches its satisfying close, weaving Herzen’s chaotic life story into a touching illustration of the limits and the consolations of philosophy.

Except for a brief prelude and coda set in Russia, “Shipwreck” gallops all over Europe. The Herzens are given permission to travel abroad for medical care — their son Kolya is deaf — and their well-appointed Paris home serves as a haven for Turgenev, the literary critic Vissarion Belinsky (Billy Crudup), and the others. They’re also drawn by the lack of censorship, but this proves paradoxically confining; when anything can be said, they feel, nothing is heard sufficiently. Or, as the dependably quotable Belinsky puts it, Paris is “like a zoo where the seals throw fish to the public.”

Much of the first play’s greatness stemmed from its deft intermingling of private emotions and public declarations, particularly within the family of the wastrel and burgeoning anarchist Michael Bakunin (Ethan Hawke). Several of the characters have begun to raise families of their own, and in the first scene of “Shipwreck,” Natalie Herzen heralds an end to the romantic upheavals: “Now grown-upness has caught up with us … as if life were too serious for love.”

But this statement proves just as fallacious as so many of the group’s lofty political pronouncements; in fact, the second act of “Shipwreck” is largely given over to a love rectangle among Herzen, Natalie, a virile German poet named George Herwegh (David Harbour), and his adoring wife Emma (Bianca Amato).

The complications from this two-family commune provide a wounding counterpoint to Herzen’s arduously conceived notion of freedom, one that slowly but firmly shifts away from his earlier utopian fantasies:

“Freedom is what we give each other, not what we take from each other like a fought-over loaf. We balance what we give up against our need for the cooperation of other people — who are each making the same balance for themselves. What is the largest number who can pull this off? I would say it’s smaller than those utopian communities. I would say the largest number is smaller than three. Two is possible, if there is love, but two is not a guarantee.”

This mania for emotional and logistical equilibrium offers an insightful glimpse into Mr. O’Byrne’s performance, which somehow manages to be both compelling and bland. His Herzen is aflame with revolutionary conviction but resolutely placid in his personal dealings; his determination to comprehend the deepest tragedies from a purely philosophical stance can be maddening on an emotional level, but I believe it is appropriate both to the character and to Mr. Stoppard’s wintry tone. Mr. O’Byrne is well matched in this regard by the ravishing Ms. Ehle, who nails the confusion and sensual hunger of Herzen’s adored but unfulfilled wife.

As Mr. O’Byrne assumes center stage, several performers from “Voyage” have receded into the background. Richard Easton attacks the tiny role of a convention-bound diplomat with a baffled, uproarious gusto that is a sharp reminder of the depth of Mr. O’Brien’s cast. And Amy Irving makes a strong showing as the estranged wife of Nicholas Ogarev (Josh Hamilton), so far the least developed of the central sextet.

Bakunin is now relegated to a handful of comic scenes, one with a dyspeptic, ineffectual Karl Marx and one with an exasperated lawyer trying to help Bakunin escape a death sentence for treason. These smaller, juicier exchanges play to the strengths of Mr. Hawke, who feels more like an ensemble member. Mr. Crudup’s consumptive Belinsky remains a high point among the 36-member cast.

He and the rest of the cast are forced to vie for space alongside Mr. O’Brien’s visuals. A limping beggar, deaf Kolya portentously spinning a top, a boisterous mini-revolution (complete with a Marseillaise-singing French maiden emerging from the smoke), a nude tableau that anticipates Manet’s “Déjeuner sur l’herbe” by more than a decade: Mr. O’Brien’s stage effects are just as striking this time around, and he ends Act I with a cunning restaging of an earlier crowd scene. (Brian MacDevitt’s lighting design remains a thing of wonder here and throughout.) But the visual trickery can feel forced at times, as if masking a lack of dramatic vigor, and both he and Mr. Stoppard telegraph a central tragedy with unfortunate overstatement.

“Life’s beauty is in its flow,” Herzen maintains when this tragedy finally strikes. “Later is too late.” By this point, Mr. Stoppard has settled back into the flow of his epic, putting into motion a series of events that promise a formidable conclusion. Despite the predictable and, well, superfluous stretches in “Shipwreck,” later can’t come soon enough.

In repertory until May 13 (150 W. 65th St., 212-239-6200).