After Thea gets in trouble with the police, Oliver turns to an old flame - now a vice cop - to help track down the creator of a new designer drug with lethal after-effects.

A jewel thief named Dodger strikes Starling City, a purse snatcher targets Thea and dating anxiety hits Oliver and Diggle. Each perilous situation leads to hard choices.

The plan to kill Malcolm Merlyn goes into operation. Arrow kills one assassin who has just arrived in the city and retrieves his cellphone. It's up to Felicity to break into it and find out just who the target is. A birthday dinner for Tommy Merlyn is interrupted by his father who brings him a present. Tommy makes it clear that he is not welcome and does not want a relationship with him. Malcolm is to receive an award at a civic gala and after a heart to heart with Oliver, Tommy decides to attend. When Oliver learns that Malcolm is the target, he races to save Tommy. Once the attack begins, Malcolm and Tommy takes refuge in his office and Malcolm is about to reveal that he is the Dark Arrow but is seriously wounded before he can do so. Arrow arrives on the scene and to convince Tommy that he is there to help, reveals his identity.

Helena is back to seek vengeance, but Oliver still has feeling toward her. The Arrow must stop and kill her, but at what costs? Now that several of his closest friends know about his true identity, no one is safe.