Shadowspire, a rogue military organization with ties to Diggle's time in Afghanistan, launch an attack on the A.R.G.U.S. agents that exposed them years before. Diggle has no choice but to rely on Andy for help. Meanwhile, Felicity confronts a specter from her past while dealing with her new role in Team Arrow.

Oliver refuses to kill Malcolm in return for Thea's cure, and Malcolm refuses to surrender rulership of the League to save his daughter. Civil war tears through Star City as the two factions fight it out. Meanwhile, Felicity discovers that the Calculator is her father and tests him to see if he can be trusted.