One question that has come up repeatedly since the Arrow episode "Invasion!" has been about the images Ollie saw when escaping the fantasy world: why are Felicity and Roy among those who have died?

Well, one theory on that is based around some dialogue earlier in the episode, between Thea and Ollie.

Thea asks why Ollie can’t just for a second, accept that this is his reward for all the sacrifices he’s made. His reply? “I didn’t make those sacrifices for a reward Thea. I did what I did because I thought it was right.”

The key word is sacrifices. Everyone who Oliver sees encouraging him as he escapes from The Dominator’s trap represents a sacrifice he has made. His father took his own life so Ollie could live. Robert’s sacrifice is one Ollie did not make for himself, but was still made for his benefit. Tommy, Moira, and Laurel were all killed by villains before Ollie was able to stop them. In a way, they are sacrifices to all three of his vigilante personas. Tommy to the Hood, Moira to the Arrow, and Laurel to the Green Arrow.

As for Roy and Felicity, they represent different kinds of loss. Roy did the same thing Robert Queen did. He sacrificed himself to save Ollie. Even though Roy is still alive (so far as we know) he had to leave his home, Thea, and being Arsenal behind in order to keep Oliver safe. That’s a huge sacrifice. And much like with his father, Ollie feels guilt for everything Roy gave up, even though the choice was made for him.

And Felicity may still be in Ollie’s life, still his friend, still helping him protect Star City. But she is his lost love. They were happy together, they were engaged to be married. Now she is in a significant relationship with someone else, and he’s starting to date other people as well. He sacrificed their life together, and now that life is lost. (I am not saying they won’t find it again in the future, they might, so please don’t think I’m attacking any ships. I’m just talking about where we are now, 100 episodes in.)

(Photo: The CW/Warner Bros. TV)

Even though Felicity and Roy have survived to this point, Ollie still lost both of them. And that makes their placement with Robert, Moira, Laurel, and Tommy very appropriate.

Have an alternate theory? Share in the comments.

Supergirl airs Monday nights at 8 p.m. ET/PT on The CW. New episodes will return in January. The Flash airs at 8 p.m. ET/PT on Tuesday nights; Arrow at 8 p.m. ET/PT on Wednesday; and DC's Legends of Tomorrow at 8 p.m. ET/PT on Thursday nights. Their midseason finales are coming this week.