The night after Ezra's funeral, a Chantyman lies sprawled in the shadow of a dock warehouse in East Boston. A clipper ship is moored along the wharf, and the refrain of "Shenandoah" can be heard from the ship coming into harbor. The Chantyman listens critically and belts out his own version in a surprisingly good, albeit drunken, tenor. The companionway door on the clipper ship's poop deck opens, and Brant emerges cautiously. The Chantyman accidentally lurches forward, and Brant threateningly turns his revolver on him.
Brant realizes his error, and the bawdy Chantyman asks him if he might need him for his next voyage. When Brant turns him down, the Chantyman laments that "Everything is dyin'" these days, noting the deaths of Abe Lincoln and the great Ezra Mannon. Brant changes the subject and gives the Chantyman a dollar to go drinking. To Brant's dismay, the Chantyman begins to sing "Hanging Johnny" and teeters off.
Christine, dressed in black, emerges from the darkness. The lovers meet on the poop deck. Christine begins to tell Adam what has transpired; she has come because her children are out visiting friends. The two retire to the cabin to speak in private. Lavinia and an enraged Orin appear on the deck.
The scene fades to black. When the lights return, a section of the ship has been removed to reveal the interior of the cabin. A haggard Christine finishes her story while her children listen on the deck above. Brant laments his cowardice. The two decide to flee to China on a passenger ship and seek out their Blessed Islands. Fearing the hour, Christine turns to go, and the lovers painfully bid each other farewell.
The children enter the cabin. Orin moves to follow them, but Lavinia restrains him. They must do all according to plan. If they are caught, no justice would be done. Orin slips out. When Brant returns, he re-enters and shoots him with his pistol almost at Brant's body. Lavinia stares at Brant's face, and then orders Orin to make it seem that Brant has been robbed. She forces herself to wish the corpse peace.
Orin returns and strangely notes Brant's resemblance to his father. The scene is like his dream: he has killed him before, over and over. Perhaps he has even committed suicide. If he had been Brant, he would have done as he did—loved Mother and killed Father. "It's queer!" Orin exclaims. "It's a rotten dirty joke on someone!" Lavinia rushes him out.
As Travis Bogard notes, O'Neill considered Act IV of "The Hunted" the "center of the whole work." This act moves the audience from its primary locale at the Mannon manor to the East Boston harbor of the drunken Chantyman. Lest the Chantyman appear merely colorful or as a means of providing one of Mourning's few moments of comic relief, Bogard implicitly suggests that we should consider the scene's significance within the context of O'Neill's oeuvre.
For Bogard, Act IV returns to the mood and manner of O'Neill's early sea plays with the same exacting detail in setting, costume, and set design, but in a more melancholic or nostalgic mode. The drunken Chantyman appears as a figure of his erstwhile poet-heroes, the troubadours-of-the sea. Here, O'Neill's former protagonist appears old, useless, and marginal to the tragedy. The Chantyman sings a chorus of "Shenandoah," drunkenly relates the theft of his cash, and brags of his ability to bring a crew into working order with his singing. He laments the coming of steam to ships and the death of the old days. As Bogard notes, the "exit of the chantyman is the last glimpse O'Neill was to give his audiences of the protected children of the sea."
The Chantyman is also a prophetic figure, speaking portentously of Lincoln and Mannon's deaths and lugubriously disappearing into the night with the dirge "Hanging Johnny" on his lips. Its lyrics oppressively foreshadow the deaths to come: "They says I hangs for money/ Oh, hang, boys, hang They say I hanged my mother/ Oh hang, boys, hang!" Christine will then remark once more on the fate the drives the players to their ruin: "I'd planned it so carefully," she says, "but something made things happen!"
The scene of the Chantyman gives way to frantic, melodramatic plotting between the two paramours. The dramatic irony of their scheming, in which they desperately rehearse their dreams of the Blessed Isle and Brant decides to relinquish his ship, is that the children are watching, poised to exact their vengeance. For the second time, Lavinia, this time with her brother in tow, catches their mother in the sexual act. This scene of watching rehearses a familiar infantile fantasy of the mother's betrayal, by which the child sees the mother with her rival beau. The set design emphasizes the voyeuristic nature of this scene by cutting away a section of Brant's ship, giving the audience a view upon their intimate exchange.
Upon witnessing his mother's betrayal, in which she chillingly echoes the reveries from their own love affair, Orin flies into a jealous rage and kills Brant soon thereafter. Note the physical proximity involved in the deathblow: Orin stands almost at Brant's body, emphasizing their relation as doubles. Brant's murder realizes Orin's queer nightmare: once again, he has killed the same man, father, and perhaps even himself. As he murmurs, the rival Brant is also his double. If he had been Brant, he would have only done the same—that is, loved Mother and killed Father.