Star City is attacked by a man known as the "Calculator" aka Noah Cuttler (Tom Amandes), who's using an old friend to do his dirty work.
The Arrow season 3 finale has come and gone. After a season full of Oliver struggling with the question of "who am I?", he's answered the question as Ra's al Ghul is about to destroy Starling City.
Team Arrow returns to Nanda Parbat to stop Ra's and Oliver from unleashing the Alpha Omega on Starling City.
It's been three weeks since Oliver took up the roll of Ra's al Ghul's heir, he now returns to Starling City on a mission.
Oliver has to take actions to save Thea after Ra's al Ghul's attack.
Oliver is still trying to consider what to do after Roy turned himself in. That gets more complicated when a metahuman shows up in Starling City.