[Warning: The following contains spoilers from Monday's Supergirl. Read at your own risk!]
Both J'onn and M'gann managed to escape the genocide of their race by the white Martians and find refuge on Earth. However, it turns out that M'gann is not who she says she is. Monday's Supergirl gave a little more insight into how she ended up on Earth — a nonsensical story about a white martian that had a change of heart and helped her escape the most deadly internment camp on Mars. It turns out though that M'gann isn't a green martian at all. The closing moments of the episode revealed that she's actually a white martian.
This brings up a few questions. Why did M'gann show herself as a green martian to J'onn in the first place if that wasn't who she was? If she wanted to keep her white martian identity a secret, it would have been better not to show herself at all. Perhaps she wants to continue the white martian agenda or eradicating all green martians, in which case she's reeling J'onn in until she can kill him and officially exterminate the race her people set out to destroy.
The third possibility is that part of M'gann's story was partially true. She was a white martian guard that had a change of heart and had to flee Mars before her superiors tried her for insubordination. There's little chance that J'onn would be willing to make peace with a white martian after they murdered is family and everyone he knows — but the storyline would fit into Supergirl's alien immigration metaphor they've been pressing hard for two episodes in a row.
First Kara (Melissa Benoist) had to learn to get over her Daxam prejudice to help Mon-El (Chris Wood). J'onn being able to forgive M'gann for her kind's transgressions — only if she herself disagrees with the white martian agenda — would be the next step in sending a message about aliens, even those from warring species, cohabiting for the better good. If these two can learn to accept each other, it sends a strong message to the audience at home about being able to accept people who are different from you. That seems to be the show's main cause this season, and is coming to a head at a time when our country is very divided in the final stages of one of the most contentious presidential elections in American history.
Before any of that potential healing can begin though, J'onn J'onzz will have to suffer the heartbreak of finding out, once again, that he is truly the last surviving son of Mars — and that won't go over well no matter what M'gann's intentions are.
Supergirl airs Mondays at 8/7c on the CW.
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