Actor Stephen Amell arrives at the 2014 People's Choice Awards in Los Angeles, California January 8, 2014
Actor Stephen Amell arrives at the 2014 People's Choice Awards in Los Angeles, California January 8, 2014. REUTERS

"Arrow" Season 2, Episode 20, titled "Seeing Red," aired on The CW on Wednesday, Apr. 23. Many fans are calling it the saddest Arrow episode ever. Moira Queen (Susanna Thompson) makes the ultimate sacrifice after the Black Canary (Caity Lotz) decides she should not be with Oliver Queen (Stephen Amell).

Spoiler alert: This recap contains major spoilers on Arrow Season 2, Episode 20 ("Seeing Red"). Read at your own risk.

Roy Harper (Colton Haynes) nearly kills Thea Queen (Willa Holland) in a fit of rage. Deathstroke aka Slade Wilson (Manu Bennett) kills Moira Queen. A lot has happened in Arrow Season 2, Episode 20. Before her sudden death, Moira tells Ollie she knows he is the vigilante in the hood and she is proud of him.

In Arrow Season 2, Episode 20, Oliver believes Roy Harper can overcome the maddening effects of Mirakuru. But Black Canary wants him dead. Sin (Bex Taylor-Klaus) makes a statement between Sara Lance (Canary) and Roy Harper.

Here is a recap of the highlights of this week's new Arrow Season 2, Episode 20:

- Moira Queen tells Sebastian Blood (Kevin Alejandro) she is quitting the race for mayor. But Oliver Queen later changes his mother's mind. In the same conversation, Moira hints to Ollie she has known for a year now that Oliver Queen is The Arrow.

- Thea Queen lures Roy Harper into Verdant, thinking she could help him. But in Roy's Mirakuru-induced hallucinations, Thea is asking him to kill her. Sara Lance aka the Black Canary points a gun at Roy, and he asks her to "please" kill him. But Sin blocks Sara's shot.

- Sara says she has been in the darkness for so long. Oliver Queen should be with someone who can harness the light that is still in him. She breaks up with Oliver on the same day that he asked her to move in with him.

- Thea, Oliver and Moira are in a limo after the Queens' political rally at Verdant. Moira is in the middle of saying something about Malcolm Merlyn (John Barrowman) when a collision occurred, scattering the limo's glass window. The next thing viewers saw was the Queens tied-up in a forest, reminiscent of Shado's (Celina Jade) death.

- It is revealed that Oliver Queen has gotten a girl pregnant when he and Laurel were still together -- way before the Queen's Gambit tragedy. Oliver was made to believe that the girl had lost his baby. It seems the viewers will know more about this in Arrow Season 3.

Laurel Lance (Katie Cassidy) appears in a flashback, but was not in the Arrow Season 2, Episode 20 present timeline. But she has an idea on who could be working with The Arrow. Now that Sara seems to be coming back to the League of Assassins, will she convince her little sister to stay in Starling City?

The manner by which Moira Queen died in Arrow 2x20 makes this episode the saddest ever, according to many fans talking about the series in social media and forum sites. In the next new episode, the synopsis hints Oliver would give himself up to Slade so he could kill him once and for all.

The evil nature of Deathstroke could happen to Roy Harper, too. How will Oliver Queen help him? More important, who will help The Arrow now that the Black Canary has left? Back to the original helpers: Felicity Smoak (Emily Bett Rickards) and John Diggle (David Ramsey).

WATCH: Arrow Season 2, Episode 20 Promo Video on YouTube (The CW clip)

Arrow Season 2, Episode 21, titled "City of Blood" airs on The CW next week, Apr. 30.

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