The train station is especially crowded with supporters of the Slavic movement. Volunteers (people who join the war in support of their Slavic brothers) abound.
Koznyshev gossips with a Princess about the latest war news. She tells him that Vronsky is also on the train. His mother is saying good-bye to Vronsky as he heads off to war.
Someone makes a grand speech praising the volunteers and whips the crowd into frenzy.
Oblonsky spots Koznyshev and urges him to make a speech as well, but Koznyshev refuses, saying that he's off to visit Levin.
Oblonsky tells him to say hello to Dolly, and to tell her that he's been appointed to the post he was after. Oblonsky says it's a pity that Koznyshev is leaving today, as tomorrow he's throwing a dinner party for two men who are leaving to join the war. One of them is Veslovsky (the young guy who caused trouble by flirting with Kitty), who has gotten married.
Distracted, Oblonsky drops five rubles into a collection box, saying that he can't help but donate money to the cause.
He is surprised to hear that Vronsky will be on the train, but he recollects himself. He forgets how lovingly Vronsky sobbed over Anna's corpse and views Vronsky as an old friend and hero.
The anonymous Princess informs Koznyshev that Vronsky is also taking along a squadron of men at his own expense.
The Princess points out Vronsky, his mother, and Oblonsky, who is talking to them excitedly. Vronsky is paying no attention.
Vronsky turns around, probably at Oblonsky's behest, and raises his hat to Koznyshev and the Princess. His face is full of suffering and unhappiness.