This article contains spoilers for the Supergirl season three episode – Midvale.
Supergirl does Riverdale in the almost all-flashback episode called Midvale. In an attempt to help Alex feel better after her breakup with Maggie, Kara borrows J'onn's car/spaceship and drives her adopted sister to their home in Midvale to spend time with their mother Eliza. We then hop back in time to when Kara first came to Earth, and she and Alex were just getting to know each other — and weren't friends yet.
Following in the footsteps of the recent CW hit Riverdale, we get a dead body, a teacher/student relationship, and a mystery to solve. Kenny, a friend of both girls, uses a telescope for a project to map the stars, but ends up taking photos of things he shouldn't. This gets him killed. He had last spent time with Kara in the woods, where he tried to kiss her. Kara is shocked by his death and started looking into it, finding his missing laptop and getting the images decrypted by Clark's friend Chloe (Smallville reference?). They find a photo of a teacher making out with a student and tell the cops.
Then Kara and Alex are run off the road and a certain it's the teacher — except his student gives him an alibi. Kara saves them, but this leads to a visit by Agent Noel Neill, who tries to warn Kara off from using her powers. Neill looks just like Kara's mom, Allura, and we find out shortly after that it's on purpose since she is actually J'onn. It turns out that the other photos on the laptop show the Sheriff doing a drug deal, and he is about to kill Alex for the laptop when Kara speeds in and saves her. The two bond and are on the way to becoming the sisters we know now. Then they pack up and head back to National City.
Izabela Vidovic and Olivia Nikkanen did a great job playing the young versions of Kara and Alex. I was a bit shocked when it went back to current time, having gotten used to those versions of the characters. Although, Vidovic reminded me more of Laura Vandervoort — the Kara from Smallville.
The episode was good at building the early stages of the characters we see today. Not sure I understand how J'onn shows up being as Eliza believed him to be Hank Henshaw… so he must've been watching Kara and felt a visit was in order. Erica Durance using the name Noel Neill is a very nice nod to the original Lois Lane from the George Reeves Superman series. The Chloe reference will be interesting as it ties into Smallville, but the character was also worked into the comics, as well. We'll have to see if this was just a name drop or a setup for something more. The one reference I haven't been able to solve is the car's license plate: LOST176. They showed it a couple times, making me think there is something there — but I'm not sure what it ties to yet.
In the previews for next week, it appears that the person who woke up on the Kryptonian ship might just be Mon-El, which really opens up a lot of questions. And he appears to be different, which makes me wonder if he comes back in time from say… the 31st Century where the Legion of Super-Heroes hang out.