Oliver gets sent down to Level Two of the prison to search for The Demon, and the identity of the prison mastermind is… not really a surprise. 

Previously on ARROW… 

In case anyone hasn’t figured it out yet, Slabside Prison, where Oliver has been sentenced, isn’t really on the up and up. Under the care of Dr. Jarrett Parker, Oliver gets transferred down to Level Two of the prison for further “treatment” of his anger. To the surprise of no one, Level Two is populated by the worst of the worst, but the baddest of them all is probably Dr. Parker himself, who has been experimenting on prisoners. And some of them don’t make it out of his lab alive. 

But what does surprise Oliver down in Level Two is the identity of The Demon, the prisoner who orchestrated most of his problems with Brick, Crimson Tiger and the Villain Formerly Known as Stardust: Talia al Ghul, the daughter of Ra’s al Ghul and the sister of Oliver’s former wife, Nyssa. She’s been sent to Slabside after running afoul of some old associates in Gotham – a nice little tease. 

Talia has orchestrated all of Oliver’s troubles because she knows of a way out of Slabside and she wants Oliver to help her get out. When she agrees to Oliver’s conditions – to find out what Dr. Parker was doing in his secret lab – the pair team up to get her out of there. Oliver stays, but only after he downloaded all the information from Parker’s computer to a flash drive and gives it Talia to give to Felicity. 

Oliver’s current wife, meanwhile, continued her search for Ricardo Diaz, enlisting Laurel as her new ally as they track The Silencer. But when Felicity learns that Oliver was moved into Level Two, she and Laurel get Dinah to try and help them figure out what’s going on.

With the reference to Gotham from Talia, it’s nice to see the start of a quasi-Birds of Prey team, with Felicity serving as the Oracle stand-in, especially with the tease in the Flash-Forward/Sideways/Whatever last episode. And Felicity eventually manages to trace The Silencer to Russia, where we see Ricardo Diaz has Anatoly by the throat. 

Meanwhile, over at ARGUS, Diggle gets Curtis to do some field work, having him pose as a doctor to facilitate capturing an arms dealer who’s trying to get his hands on some chemical weapons. It’s a nice little interlude that gets Curtis back in the game after he spent some time as a desk jockey. 

There’s no mention of Roy and William or any continuation of the flash we got last episode, but this was still another fantastic chapter in what is turning out to be an amazing season.