Via flashbacks on Arrow Season 3 Episode 6, we see that Maseo needs Oliver to remember where an informant for China White stashed vital information
Elsewhere, Roy shares a secret with Felicity.
Felicity sends Oliver, Roy and Diggle to check something out. They find a room full of dead people and a lot of drugs. Someone was trying to send a message and Roy spots the word "Guilty" in blood on the floor.
Oliver sends Roy home to get some rest and then flashes back to the first time he learned about China White in Hong Kong.
Roy asks Felicity to test him for Mirakuru.
Laurel is training with Ted but he wants to close up shop and go home. Moments later the next gang member is found at his place. Ted walks out of the back with a smile and finds Arrow poised to shoot him.
Laurel steps out and gives Ted an alibi, as well as noting the hanging body wasn't there when they left.
Roy is free of Mirakuru. He shares his secret with Felicity. She is worried.
Captain Lance questions Laurel about her trainer who she just so happened to have dinner with. Oliver and Laurel have words over her training and Ted Grant.
Flashback to the little kid in Hong Kong. Something about memory.
Felicity digs up that Ted "Wildcat" Grant was a southpaw who was never believed to be a suspect in a murder from six years ago. Oliver heads over and spots the vigilante stuff on Ted's desk, as well as brass knuckles. Ted says he's being set up. He used to be a vigilante. He was Arrow before Arrow.
Ted wasn't news, because he stuck to the Glades. Ted pointed out that The Arrow is a bit hypocritcal talking about people who wear masks being like serial killers.
Ted admits to beating someone to death six years ago. While he avoided jail time, he's been living with the guilt ever since.
Oliver tries to get Oliver away from Ted, but she's sure he wasn't involved now. Oliver wonders if Laurel knows Ted beat someone to death six years ago. No. She also didn't know he was a vigilante. Laurel and Oliver have words about her training.
Felicity wants to talk with Roy. She created a virtual autopsy of Sara and discovered that everything she couldn't reconcile with a regular bow could be counted for if they determine Roy did it with Mirakuru in his system. Height, velocity and angle would all fit.
Felicity thinks it's possible that if Roy killed Sara it would have burned out any remnants of Mirakuru in his system, which is why he might be showing clear now.
While The Arrow and Ted are talking to a guy Ted used to pall around with, another archer shoots at them and then Ted is arrested. Someone wearing Ted's old gear is responsible for doing it.
Roy tells Oliver and Laurel that he killed Sara. Roy tries to apologize to Laurel, but she won't hear it. Diggle tries to keep him there and Oliver lets him go. Blood tests were inconclusive.
Roy's trouble sleeping started right when Sara was killed, that and the other forensic evidence leads Felicity to believe it was him.
Flashback: This is where the memory part comes into play. The little boy's mother gave him hints how to recover lost memories. If only it were that easy.
Laurel wants Ted to be straight with her. If the DA's office doesn't press charges, he'll go free, so she's the best person to talk to. Isaac Stanzler was Ted's guy in red. He went bad. Ted didn't murder the guy he admitted to with The Arrow. Stanzler did it, but Ted takes responsibility.
Isaac wants to kill Ted, but he'll talk with him first. He was tortured by the gang for months, apparently. They take off in a car and Laurel dials Felicity. She must be high up on Laurel's speed dial. An SUV comes directy toward them. It's Diggle. Laurel can't flinch so Diggle swerves. Stanzler grabs the wheel and Oliver is tossed off his bike. Roy pulls up behind. Laurel is in the car, unconscious as it goes up in flames. Roy starts using his jumpity jump style to kick the guys ass -- he says Oliver will abandon him.
Ted calls Oliver out of the shadow. They disagree over Laurel's training first. Ted also thinks he should have cut Isaac loose sooner to keep him from harm. Oliver disagrees.
Oliver goes to see Laurel in the hospital. He asks her to trust him about Roy and then he gets Roy to remember killing the cop. He realizes either way, he's still a murderer.
Laurel wants Ted to continue training her regardless of what "robin hood" wants. She realizes that she wasn't afraid as things were going down last night, but knew what to do and did it. She wants to keep on that path.
When Isaac is being taken away in cuffs, Cupid pops in.