2.21 = City of Blood

2x18 synopsis:
Arrow Episode Guide 2014 Season 2 - Deathstroke, Episode 18 | TVGuide.com
Arrow Episode: "Deathstroke"
Season 2, Episode 18
Episode Synopsis: Slade makes his move against Oliver and the repercussions are severe. Oliver desperately tries to protect his family, but one key player on his team questions his decisions. Meanwhile, Isabel attempts to take Queen Consolidated away from Oliver. Original Air Date: Apr 2, 2014

2x19 - 4/16
2x20-4/23
2x21-4/30
2x22-5/7
2x23-5/14

And tyftnt!