'Tis the season for superhero fans and Riverdale alums - CW premieres new seasons of all its hit shows this week. DC comic book fans get to see what Kara Danvers, Barry Allen, Oliver Queen and the Legends have been up to when their respective series return this week. The network also drops new dramas Dynasty and Valor. The former is a reboot of the scandalous '80s soap about an uber-rich family. The latter centers on a group of elite U.S. Army helicopter pilots after a return from a dangerous mission. But perhaps the most anticipated return is the second season of Riverdale, the pulpy, critical darling that stole hearts last fall with juicy teen drama and small town scandal.
SEASON PREMIERE: Supergirl, 8 p.m., CW: Kara grapples with the loss of Mon-El by throwing all her energy into being Supergirl and battling a mysterious new threat against National City.
SERIES PREMIERE: Valor, 9 p.m., CW: An elite group of Army helicopter pilots deal with the aftermath of a top-secret mission in Somalia that went terribly awry.
Halloween Wars, 10 p.m., Food Network: Two teams compete in "Hayride of Horror" where they'll see what happens when the pumpkins they're carving come to life.
SEASON PREMIERE: Teen Mum, 10 p.m., MTV: In the second season, it's time to catch up with British moms Chloe, Megan and Mia, and two new moms are introduced.
Finding Your Roots with Henry Louis Gates Jr., 8 p.m., PBS: Fred Armisen, Christopher Walken and Carly Simon learn about grandparents whose real identities had been a mystery to them.
SEASON PREMIERE: The Flash, 8 p.m., CW: The fourth season begins with a powerful villain threatening to destroy Central City if the Flash doesn't appear. But Cisco makes a risky decision to break Barry out of the speed force prison.
SEASON PREMIERE: DC Legends of Tomorrow, 9 p.m., CW: The Legends are relieved of duty when they break the timeline, but Sara, Nate and Ray make a plan to steal the Waverider back from the Time Bureau to stop Julius Caesar.
Trick 'r Treat, 10 p.m., Syfy: This Halloween classic is an anthology shocker with four interconnected stories of terror and gore.
SEASON PREMIERE: Riverdale, 8 p.m., CW: The second season immediately addresses that dramatic cliffhanger from last season's finale when Archie struggles with the aftermath of the diner shooting and Veronica's father arrives in Riverdale earlier than expected.
SERIES PREMIERE: Dynasty, 9 p.m., CW: A reboot of the sudsy '80s soap premieres and follows two wealthy families feuding over their fortunes and children. First up, one mogul's daughter seeks revenge after he promotes his new bride over her.
SEASON PREMIERE: Mr. Robot, 10 p.m., USA: Elliot "gets woke" in the third season and realizes he needs help from Angela.
SERIES PREMIERE: The Story of Us with Morgan Freeman, 9 p.m., NatGeo: Morgan Freeman travels the world exploring different concepts of freedom and what that means to different people and cultures.
SEASON PREMIERE: The Shannara Chronicles, 10 p.m., Spike: Wil's new life is interrupted by a mysterious new figure and Eretria is reunited with someone from her past in the second season of this fantasy series.
SERIES PREMIERE: I Love You, America, midnight, Hulu: Sarah Silverman's new comedy variety show that also features interviews and insight from those who don't share Silverman's worldviews.
SEASON PREMIERE: Supernatural, 8 p.m., CW: The lucky 13th season sees Sam and Dean picking up the pieces after the loss of their mother, Crowley's demise and Castiel's death.
SEASON PREMIERE: Arrow, 9 p.m., CW: Oliver deals with the aftermath of the explosion on the island in the sixth season.
Contact Chelsea Tatham at [email protected] Follow @chelseatatham.