Menelaüs tests the Greeks’ resolve by proposing retreat, but Diomedes threatens to kill anyone who tries to leave before Troy is taken. In response to advice from the seer Calchas that this will not happen unless Achilles’ son Neoptolemus is present, Odysseus and Diomedes set sail for Scyros to fetch him. Eurypylus, leader of the Cetaeans, comes with his army to the aid of the Trojans. He is the grandson of Heracles and the son of Telephus, who once fought Achilles. Like Penthesileia in Book 1 and Memnon in Book 2, he is royally received. There is a long description of his shield, which depicts the Labors of Heracles; this complements the description of Achilles’ shield in Book 5. The second half of the book tells of various encounters in battle between the Greeks and the Trojans, with Eurypylus leading the Trojan attack.
The testing of troops is inspired by a similar episode in Book 2 of the Iliad, the battle scenes by parts of Book 11. Eurypylus figured in the Little Iliad and in a tragedy of Sophocles, now lost, named after him.