SPOILER WARNING: This article contains major spoilers for “The Thanatos Guild,” the latest episode of Arrow.
Arrow just said goodbye to Thea Queen. In "The Thanatos Guild," the latest episode, Oliver's younger sister went off with Roy Harper and Nyssa al Ghul for an adventure of her very own.
As Thea prepared to leave Star City with Roy, she was attacked by the Thanatos Guild, a splinter faction of the League of Assassins founded by her father Malcolm Merlyn. They believed she was the key to finding Malcolm's ultimate goal, though they weren't sure who or what that was.
The appearance of the Thanatos Guild led Team Arrow to track down a puzzle box, which Felicity unlocked with her math skills. Inside the box, they found what appeared to be a blank piece of parchment. Later, during a skirmish with the Thanatos Guild, Thea got some blood on it. Thea's blood spread throughout the parchment, revealing a hidden map.
Back in the bunker, Team Arrow discovered that the map led to something very dangerous: three new Lazarus Pits. However, they realized that they wouldn't be able to prevent the Thanatos Guild from finding those Lazarus Pits forever. Considering that, Thea decided to forget retirement; instead, she chose to go with Nyssa to destroy the Lazarus Pits.
Roy wasn't about to let Thea be the one who got away (again). During a final heart-to-heart with her, he revealed that he would join her and Nyssa on their mission, despite his earlier hesitation to return to vigilante life. So, at the end of the episode, the three Arrow characters rode off into the night to pursue a new adventure: righting Malcolm Merlyn's wrongs.
"We’re very sad to see Willa [Holland] go. She’s been a critical part of Arrow since its inception and a wonderful and talented person to boot," executive producer Marc Guggenheim told The Hollywood Reporter. "But we’re in our sixth season now and supportive of her wish to stretch her legs and pursue other creative opportunities. The door is always open for Willa to return if she has a hankering to."
Holland has been a part of the series since the show's first season. However, she took on a reduced role in the past two seasons, appearing for 14 episodes in Season 5 and 10 in Season 6. Since her exit was open-ended, there remains a possibility of a return somewhere down the line.
Starring Stephen Amell as the Emerald Archer, Arrow airs Thursdays at 9pm ET/PT on The CW. The series also stars Emily Bett Rickards, David Ramsey and more.