For all the shocking twists and turns of Homeland's season finale, the most surprising realization came after it was over. Underneath the moral and political complications of terrorism policy, beneath the sensitive portrayals of the mentally damaged, lies a simple retelling of the story of Cassandra.
You remember Cassandra. She was given the gift of prophecy, but then she pissed off Apollo, who put a curse on her that no one would believe her predictions.
Carrie's mental illness becomes the modern simulacrum of Apollo's curse. Makes perfect sense, doesn't it? She's gifted with a brain that functions in marvelous ways, but her malfunctions deprive her of all credibility.
In this scenario, Brody clearly becomes Odysseus, who is often described as "Odysseus the cunning" or "cruel Odysseus," depending on whose side you're on. He returns to his long-suffering wife after journeying through torment, war, and unimaginable delight, all the while expecting nothing to have changed at home.
Like Odysseus, he's clearly both a hero and a villain, and neither aspect negates the other. (Is it an accident that Carrie's "wise man" is named Virgil? For The Aeneid's Odysseus is a villain, only Homer's is heroic. In the end, only Virgil trusts Carrie's instincts.) Only Carrie is able to process these two selves, and her knowledge is rewarded with ostracization, derision and finally self-mutilation.
For Carrie's prophecy has now been ignored, and lost even to herself. The Trojan Horse has now been planted at the highest echelons of the government.
In conclusion, I give you my favorite retelling of Cassandra, by ABBA: