Twice in the Iliad (4.370-418, 5.800-813), a rousing tale of Tydeus’s embassy to Thebes is told to his son Diomedes. Is it a coincidence that this rather obscure story should constitute Homer’s only extended allusion to the famous war of the “Seven against Thebes”? Does this choice merely reflect the rhetorical needs of Agamemnon and Athena, who seek to stir Diomedes to deeds of valor? I argue that the two passages, taken together, reveal a unitary conception and literary form that go well beyond the rhetorical needs of these speakers. What is really at work in the choice of this episode is the poet’s instinctive habit of seeking out and refashioning “off-center” but highly exemplary episodes within larger traditions.