Homer's Iliad. Book XVIII

Book 18 of the Iliad addresses the consequences of Patroklos’ death for both the Trojans and the Achaians. Achilles, moved by unbearable sorrow, chooses to enact his plan for revenge and vows on the funeral pyre of Patroklos that he would kill Hektor. On Olympos, Thetis tries to discourage her son from these purposes for she knows he will die if he goes back to the battlefield. However, Achilles stands fast and obtains from Hephaistos new armor.