Yelena enters the room and informs Voynitsky that her husband has sent for him. Begging her father to reconcile with the professor, Sonya exits with him. Yelena and Astrov say their goodbyes. The doctor makes one more attempt to convince her to stay; Yelena declines. The two shake hands, and Astrov reflects on her stay at the estate, echoing Sonya's remarks from Act III. Yelena's idleness is infectious, disruptive to everyone on the estate. Though he claims to be joking, he is certain that had she remained, great "devastation" would ensue. Abruptly he breaks from his ominous prophecies: "Well, you'd better be on your way. Finita la commedia! ("The comedy is finished").
Yelena takes his pencil as a memento, and the two part. The other members of the household enter. Apparently Serebryakov and Voynitsky have reconciled; "Everyone will be just as it was," the latter murmurs grimly to the enthusiastic professor. Serebryakov makes a pompous exit; ironically, he repeats Maria's cry that "[s]omething useful ought to get done!" as he leaves his relations to their toil. Yelena and an apologetic Voynitsky share a brief, moving farewell, Voynitsky telling his in-law that she will never see him again. Terribly depressed, Voynitsky and Sonya return to their long-deferred work; Marina sits and knits a stocking. Astrov remarks on the map of Africa. Shortly thereafter he departs after telling Sonya he will not return for a long time and takes a drink from Marina. As the sound of Astrov's harness bells ring out, Voynitsky counts the expenses ("February second, oil, twenty pounds February sixteenth, again oil, twenty pounds"). "Oh, our sins" Marina yawns; Telegin begins playing the guitar.
Voynitsky then turns to Sonya with a plea: "Oh, if you only knew how it breaks my heart!" Though sympathetic, once again his listener will not hear him. Sonya tells him that they must keep on living, that they must endure their trials without rest and wait for death, the time when God will take pity on them. Only then will they come to a beautiful life and look back upon their past miseries in peace. Laying her head on his lap, Sonya conjures a vision of heaven, and Vanya weeps. The watchman taps; Telegin plays quietly. Indifferently Maria makes notes on her pamphlet, and Marina knits. The play closes with Sonya's repeated refrain "We shall rest we shall rest!"
Once it is clear that they will part, Astrov rehearses Sonya's teasing remarks from Act III on Yelena's idleness but in a more deliberate fashion. Though he claims to be joking, it is clear that we are to take these thoughts more seriously this time. Elliptically, and almost mystically, Astrov poses Yelena and her husband as bearers of destruction. To recall the parallel Eugene Bristow draws between the ruin of the land and the ruin in the characters' inner lives, one could say that Yelena and the professor have both sent the estate ruin with their apathy and precipitated the internal crises of its members as well.
As noted in Act III, this scene also includes Astrov's famous elegiac lines: "It is strange somehow, we never got to know each other, and all at once for some reason—we shall never meet again. So it is with everything in the world." Again, one might refer this wistful goodbye to the theme of the may-have-been. Their farewell is nostalgic, the pair experiencing a loss that they (having never realized their "fascination") cannot even be certain that they suffered, not a loss, but a potential loss. Though their parting in no way reaches tragic proportions, it is filled with regret and disappointment: the misery here is subtle, intimate. One might add that this farewell evokes Voynitsky's illusions of what could have been if he had married Yelena when they first met.
The last scene choreographs a series of brief and understated farewells—between Astrov and Sonya, Voynitsky and Yelena, and Voynitsky and Serebryakov—all the more poignant in that they quietly discard, under the cover of sociability or otherwise, the tortured complications and tensions we have witnessed thus far. Astrov, for example, takes a drink, remarks idly on the climate in Africa, and talks of his horses before finally departing, with little concern for Sonya or Voynitsky. The comedy is certainly finished, and it would appear little has changed. Nevertheless, though left unstated, the misery underneath the everyday farewells is omnipresent. Note, for example, how the apparently commonplace dialogue wistfully underlines the absence left by the guests' departure: "They've gone." Marina announces after Yelena and Serebryakov have ridden off; "They've gone." Sonya repeats upon entering the room herself.