What would lead Supergirl to break her promise to her cousin and reveal her existence to the world? One thing is guaranteed: it either involves 1) aliens 2) robots 3) kryptonite or 4) super-hypnosis.
This issue starts with Kara substituting for her older cousin when he is stuck in a situation where using his powers would expose his secret identity. Situations like this is why Superman forces Supergirl to keep her existence a secret. Of course there’s probably a hundred ways he could have gotten out of his predicament without forcing Kara to work in secret. Superman’s “Supergirl as a secret weapon” plan doesn’t benefit Supergirl at all. Since she can’t risk her secret identity being revealed she is forced to live at the orphanage instead of being adopted. While flying back home she flies through the tail of a comet which is laced with red Kryptonite. Red Kryptonite: when you need something wacky to happen but you don’t want to work too hard to explain why it happened.
This time the red Kryptonite causes *shakes the Red K magic 8-ball* Supergirl to loose her memory. She lands in Smallville where she is taken in by a temporarily blind couple. Her promise to her cousin forgotten along with the rest of her memories Supergirl performs super-heroic things in public. The citizens of Smallville are ecstatic, they finally have a guardian angel again! Why Smallville is an epicenter for destruction is not explained.
Actually, Smallville is dangerous because Superboy lived there.
The married couple that Kara is staying with regain their vision and learn of her secret identity. Contrary to what Kara always thought would happen the couple accepts Kara and her secret identity. They want to adopt Kara and even help her keep the ‘Supergirl’ identity secret. They even come up with a way for Kara to leave their home through a secret passage. Kara is happy with her new family and returns to Smallville as it’s new protector.
Superman sees all this going on and won’t stand for it! You see, Superman still wants Supergirl as his ‘secret weapon’. Now that she is not hiding his plans are ruined. He decides the right course of action is to erase the memories of everyone in Smallville, Supergirl included. “But wait“, you say, “Supergirl is finally happy, a great family just adopted her!” Superman doesn’t seem to care about Kara’s feelings, all he worries about is that his plans are ruined. Erasing the minds of the Smallville populace is ethically wrong too. Someone must have voted Superman high ruler of Smallville.
Oh well, I’m sure Linda is happy at the orphanage.
On my patented Supergirl Wink © scale this issue gets: