The extended metaphor is in the lines "then inevitable disasters strike, / falling upon whole families, / just as a surging ocean swell"
Explanation:
An extended metaphor occurs when the metaphor extends, as the name implies, over many lines. or paraphrases of a text, being explained and explored by several grammatical elements and even other literary techniques.
In the text referenced by the question above, the metaphor occurs when the author states that the punishment of the gods will not only fall on the guilty person, but will drag that person's family members like a wave from the ocean.
My answer would be: the destruction wrought when ambition goes unchecked by moral constraints—finds its most powerful expression in the play's two main characters.
