Arrow is bringing back a lot of familiar faces for its eighth and final season, including Oliver Queen's younger half-sister Thea who has since become her own crime-fighting superhero.

The CW has released the official plot synopsis for the final season's third episode, titled "Leap of Faith," that has the reunited Queen siblings investigating a maze of catacombs while John Diggle teams with Lyla on a separate mission. The episode itself will be directed by longtime Arrow cast member Katie Cassidy.

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WILLA HOLLAND GUEST STARS – Reunited with his sister, Oliver (Stephen Amell) and Thea (guest star Willa Holland) find themselves searching through a familiar maze of catacombs. Meanwhile, John (David Ramsey) and Lyla (guest star Audrey Marie Anderson) partner on a special ops mission. Katie Cassidy directed the episode written by Emilio Ortega Aldrich & Elizabeth Kim (#803). Original airdate 10/29/2019.

Willa Holland's return as Thea had been confirmed earlier this month with the release of official stills from the upcoming episode, showing Thea standing alongside Oliver and Talia al Ghul in an ancient tomb. Holland had starred as Thea ever since the first season, eventually leaving the main cast to return in the occasional guest-starring appearance.

In the previously released photos, Thea was seen sporting a new facial scar as the ensemble were joined by the League of Assassins. Given that her biological father Malcolm Merlyn had once held the role of Ra's al Ghul for a time, it is unclear how her relationship with Talia has progressed into Season 8.

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Returning Tuesday, Oct. 15 at 9 p.m. ET/PT on The CW, Arrow stars Stephen Amell as Oliver Queen, David Ramsey as John Diggle, Rick Gonzalez as Wild Dog, Juliana Harkavy as Black Canary, Katie Cassidy as Black Siren, Katherine McNamara as Mia Smoak, Joseph David-Jones as Connor Hawke and Ben Lewis as William Clayton-Queen.