This Week on The CW for the Week of January 22nd

The CW's shows started settling into their post-hiatus pace this week now that the midseason premieres were out of the way. We saw some major girl power on Supergirl, a new hero rise on The Flash, Black Lightning announced his return for all the world to hear, Archie took up a new sport on Riverdale, and Oliver came clean with his son on Arrow.

But even with the shows telling stories that get us closer to some of their biggest mysteries or challenges this season -- or simply setting the stage, as is the case for the newer Black Lightning -- as always there are a few themes that carried across the network's programming as well as some curious nods and Easter eggs between the shows. While not all of the themes carried over all the shows, there were just enough little details to warrant a second look.

Legacy Casting

One of the things that The CW does especially well when it comes to its Arrowverse shows is legacy casting. Particularly on Supergirl and The Flash, it's not uncommon to see actors from elsewhere in DC movies and television appearing. On Supergirl that often means actors playing different characters from what they had played previously -- for example, Erica Durance was Smallville's Lois Lane but on Supergirl she's Kara's mom -- while on The Flash some actors reprise their original roles. Mark Hamill's appearances as The Trickster is an excellent example of that.

This week, both Supergirl and The Flash had some brilliant legacy casting. On Supergirl, the mysterious Jindah Kol Rozz was portrayed by Superman: The Movie and Superman II alum Sarah Douglas. In the Superman films, Douglas portrayed Ursa, Zod's right-hand woman which made her turn as the Kryptonian priestess aligned with Rein a perfect fit. Meanwhile on The Flash, Mark Hamill may not have appeared as Trickster, but his '90s sidekick made her Arrowverse debut. Corinne Bohrer reprised her role as Zoey Clark, better known as Prank, Trickster's love interest from the '90s television Flash series.

Riverdale Everywhere

Of the shows covered in this roundup, Black Lightning is the only one to not film in Vancouver, but that didn't exempt the newest hero on the block from having its own little Riverdale invasion. The Archie Comics-inspired show was all over The CW this week. First, Brit Morgan guest starred as Livewire on Supergirl, playing waitress on a set that looks an awful lot like Riverdale's favorite hangout, Pop's. If that wasn't enough, Morgan also has a guest starring role on Riverdale as the villain-like Penny Peabody -- who makes her return to Riverdale next week.

Meanwhile on Black Lightning, Jennifer Pierce (China Anne McClain) started dating a young man named Khalil. Many sharp-eyed viewers noticed that Khalil looked very familiar, and that's because Khalil is played by Jordan Calloway, who also plays Chuck Clayton over on Riverdale. Fortunately for Jennifer, Khalil seems to be a nicer guy than Chuck, though considering that both Jennifer's father and sister have powers, maybe it's lucky for Khalil that he's such a nice guy. We're pretty sure Chuck wouldn't fare well.

Sex Work

While there are definitely lighthearted moments on The CW, the shows do often take on more serious topics and, particularly on Riverdale and Black Lightning, one of those topics is sex work. Riverdale takes a more mixed approach. During the midseason premiere last week, it was revealed that Cheryl's mother is working as prostitute or call girl. And she has no shame about it. Mrs. Blossom is proud of her work and even enjoys it, referencing it again this week when talking about the family's history of having operated a brothel. Riverdale's other sex work reference is a little less simple. The Coopers find out that Chic (Hart Denton) does webcam work as a way to pay the bills, though Chic reveals to Betty that it also helps him escape his darkness. It's a path his little sister may well follow him on.

Meanwhile, Black Lightning takes perhaps the most serious approach to the issue. In this past week's episode, The 100 has kidnapped the daughter of one of Jefferson Pierce's (Cress Williams) former students, Lawanda White, and has been selling her services out of the Seahorse Motel. It's a horrifying and serious plot thread, but one that is, sadly, all too real with human trafficking being a serious problem around the world. Fortunately, despite Lawanda's death, there is a bit of a happy ending. The Seahorse Motel is closed down following the arrest of Lala and all the women being held against their will were rescued.

Supergirl airs Mondays at 8/7c. The Flash airs Tuesdays at 8/7c with Black Lightning following at 9/8c. Riverdale airs Wednesdays at 8/7c and Arrow airs Thursdays at 9/8c.