I Got Your Back - Arrow Season 3 Episode 1
Canary has Arrow's back in this photo from the Arrow Season 3 premiere. Was there any doubt?

Arrow Quotes

There are people in this world who deal only in extremes. It's naive to think that anything less than extreme measures will stop them.

Amanda

Laurel: Helena, you don't have to do this.
Helena: Yes, I do. Because once you let the darkness inside, it never comes out.