'Arrow' Fans React to SPOILER Leaving in "The Thanatos Guild"

Tonight's Arrow saw one mainstay make their exit -- and fans are having a lot of feelings about it.

Spoilers for tonight's episode of Arrow, "The Thanatos Guild", below!

The episode saw Team Arrow dealing with a new threat, which was introduced by an ominous warning from Nyssa al Ghul (Katrina Law). As she explained, Malcolm Merlyn (John Barrowman) had formed a rogue band of League of Assassins members in the months before his death, which became known as the Thanatos Guild.

The leader of that group, Athena (Kyra Zagorsky), had traveled to Star City, in search of Thea Queen (Willa Holland). As it turns out, Malcolm was the owner of a map that led to some sort of ancient treasure, and the Thanatos Guild believed that Thea would be able to help unlock it.

This proved to be quite a problem for Thea, who had decided to follow through with the suggestion that Oliver Queen/Green Arrow (Stephen Amell) had made in the previous episode -- that she and Roy Harper (Colton Haynes) leave Star City and try to make a better life for themselves. She and Roy reluctantly decided to help solve the problem with the Thanatos Guild, tracking down the map, and ultimately figuring out that it led to the existence of three new Lazarus Pits.

This excursion made Thea realize that she didn't want to end her vigilante days just yet, and that she would follow Nyssa to track down the remaining pits. Roy agreed to travel along, and the trio departed together.

As you'd expect, fans are having quite a reaction to Thea's surprising exit, considering the fact that she's been around since the series' inception. Here are a few of our favorite tweets about Thea's exit from Arrow.