Deaglán spends the night bound in Gallchobhar’s prison tent, weakened by pain from the stone pin driven into his neck and by earlier abuse. The battle outside eventually quiets, and Tara suddenly appears after killing or disabling the guards. She cuts him free, and Deaglán tears out the pin, which reduces the agony enough for him to think clearly. Tara explains that the Caer is in dire condition: Fiachra has destroyed outer warbands, supplies are nearly gone, and the defenders plan a desperate attack after dawn.

Tara and Deaglán try to walk out of the camp unnoticed, but Gallchobhar recognizes Deaglán before they can escape. When armed men block their path, Tara immediately challenges Gallchobhar to single combat, staking her life and demanding that Deaglán leave unharmed if she wins. Gallchobhar agrees, partly because refusing in front of both armies would make him look weak, and he deliberately has the duel staged before the Caer so King Rónán will be forced to watch.

In the public duel, Tara proves herself Gallchobhar’s equal in skill, speed, and composure, and for a time she deflects every attack while also threatening him in return. The fight slowly turns against her because Gallchobhar is larger, stronger, and better able to absorb and press through each exchange. Once Tara begins losing ground physically, Gallchobhar exploits the opening, wounds her shoulder, then cuts her repeatedly until she collapses. With Tara dying, Gallchobhar calls out to Rónán and offers a cruel bargain: he will return Tara for healing if Rónán surrenders himself. Rónán accepts, adding a demand that Deaglán be freed, but Gallchobhar ignores that part and forces the exchange anyway.

Tara is carried back into the Caer, and after she is safely retrieved, Rónán walks out and gives himself up with full royal dignity. Gallchobhar resents Rónán’s insistence that he is surrendering to King Fiachra rather than to Gallchobhar personally, but has him bound and leads both prisoners to the sacrificial platform at Lake Áras. In front of both armies, Rónán publicly denies Gallchobhar any true honor, which further enrages him. Gallchobhar then has Deaglán forced to his knees, straps the heavy silver arm back onto his stump so it will drag him down in the water, and turns the mockery into immediate violence by driving his blade into Deaglán’s stomach.