What’s next for Thea (Willa Holland)?
With Holland only contracted for 14 episodes this season, Thea was MIA on-screen. But with her return, “She’s headed in a direction that’s very similar to where her mother was before she was killed in Season 2,” Guggenheim previewed. “We’re excited about it; I’m actually really excited about her storyline because we’re taking her to a place where she’s been dealing with all of these issues the same way Oliver has, with her bloodlust and with her other elements of her past, and this season’s going to find her in a similar place but for very different reasons. There’s gonna be a great scene coming up between Oliver and Thea that’s one of my favorites on the show.”

The next hour is a big one.
“For me, [Episode] 14 is this fulcrum where a lot of the little seeds that had been planted in the first half of the season start to come to fruition,” Guggenheim teased. “You start to realize that oh, Prometheus has been setting up a chess board and the episode ends, I think, with sort of the next key move in Prometheus’ grand plan.”

Thea will also give her brother a pep talk in the next episode. “Thea’s gonna make a good case to Oliver, of all people, for all the things he’s accomplished as mayor,” Guggenheim previewed. “You start to see like, oh wait, in the first 13 episodes, he actually kind of did some stuff. And he’s not done yet. But we definitely went into the season with the goal of showing that Oliver is actually much better at this job than you might expect.”

(source)