Supergirl may have won back the trust of National City’s people in the last episode, but when Kryptonian renegade Non puts his grand plan–codenamed Myriad–into effect, the public trust becomes, well, a Non-issue. The minds of National’s citizens are enslaved, and Kara is embattled on multiple fronts. A brainwashed Lucy Lane plans to unleash the DEO’s alien prisoners, on orders from Non, including super-powered warrior queen Maxima. Joining forces with the evil alien supercomputer Indigo, Non is bent on taking control of every mind on Earth in order to save it, much like he and Astra tried to do on Krypton before being exiled to the Phantom Zone. Superman is off-world on another mission, and the military has all of National City under quarantine, but Supergirl finds help in unexpected quarters. Despite all of CatCo’s employees (including James and Winn) being held in Non’s thrall, Cat Grant is mysteriously unaffected, as is smarmy tech billionaire Maxwell Lord. Supergirl will be forced to make some hard choices to win this one, considering that Max Lord has a plan to save the day–one that will cost thousands of lives, lives that may have to be sacrificed in order to save millions.
Meanwhile, unaware of what’s going on back in National City, Supergirl‘s adoptive sister Alex Danvers and former DEO chief Hank Henshaw/J’onn J’onzz are on the run as they try to learn more about Alex’s missing father. Travelling incognito as a mother and son (thanks to a blonde wig and J’onn’s Martian shape-changing abilities), the duo makes their way to Alex’s mother (original Supergirl Helen Slater, star of the 1984 film!). Once they’ve learned about what’s happening in National City, will they be able to stay on mission and try to find Jeremiah Danvers, or will they turn back to try and help Supergirl save the day? All this and a fact-finding mission to the Fortress Of Solitude, a near-cameo by the Man Of Steel, and a very funny, very meta joke about Harrison Ford.