Thea Queen didn't know until last week's episode that it was ultimately her hand that killed Sara Lance (though Malcolm Merlyn drugged her to maker her do it). Ra's al Ghul must have been watching, because this episode opens with him chllin' in a huge bathtub when a pissy Nyssa (I bet that was her nickname in middle school) storms in and says Sara's killer --- who she still believes to be Ollie --- is alive.
Ra's calmly says he already knows that, and that Ollie isn't actually Sara's killer. Nyssa says Ollie's got to die anyway, and presumably teleports directly to Starling.
I now Ra's likely knows all this because he's got League of Assassins eyes everywhere, but I like to think he's just a big fan of the show. Like, in his spare time, he concocts theories about how Tommy Merlyn might not be dead. He ships Ollie and Amanda Waller.
In the Arrowcave, Thea, Malcolm and Ollie train while Malcolm tells Ollie that he's been wasting his time preparing to "bring a bow and arrow to a swordfight." Is that a euphemism? Anyway, Malcolm suggests Ollie and Thea stay in the Arrowcave for safety since Dig has apparently rigged Verdant up with iron gates and the laser security system from the movie Entrapment. Ollie says they'll stay in Theapartment, thanks, in one of his many acts of jerky defiance this episode.
As if she absolutely couldn't wait to tell people, Thea spills that she threw the arrows that killed Sara to both Roy and Laurel in record time. Roy already knew, but Laurel didn't. She actually takes the news in a surprisingly measured way, telling Thea it wasn't her fault if she was being mind controlled. She says Malcolm's going to get his, though.
Laurel goes to the Arrowcave and tells Ollie she can't remember Sara's smile, one of two times Laurel says something mega-sad about the loss of her sister, but also perhaps indicating she's suffered a serious concussion. Laurel asks if Team Arrow is going to find Sara's killer, and Ollie lies, "We will." Laurel calls him out on it and tells him Thea spilled the beans. She says Team Arrow has got to take down Malcolm.
Ollie, the control freak that he is, says the team needs Malcolm to fight Ra's, and, "this is the way it has to be," like he's a dad telling his daughter to eat all her peas.
Then Ollie, who is really on a roll at this point, bursts into Theapartment and starts yelling at his sister for telling another human being about this immense burden of guilt she has, because they're still in danger. Thea says she and Ollie aren't in danger anymore, because she has handed Malcolm over to the League.
Cut to: Malcolm walking away from some warehouse somewhere, the most common location in all of Starling City. Laurel, in full Canary gear, confronts him and initiates a fight. It doesn't go well for her, so she pulls a gun. Before she can fire, however, the League shows up.
Nyssa fares much better, eventually subduing Malcolm. The assassins drag Malcolm away and Nyssa tells Laurel she "can rest now" because Sara's killer is going to be horribly executed.
Laurel returns to the Arrowcave and Ollie starts yelling at her, as he does, and it's a real doozy this time. He tells her that she "let her emotions dictate her actions." Next thing you know he's going to start blaming her hatred of Malcolm on misandry and saying "not all men" killed Sara.
Then Ollie, moral arbiter of everything, gets up on his high horse and says Team Arrow has to go save Merlyn. Everyone rightly looks at him like he's bananas, but he says Thea's going to regret handing her father over to be executed. "I'm trying to save Thea's soul," he says, and somehow no one makes a jerk-off motion at him.
Smoak does some searching and finds Nyssa and Malcolm at a helipad. Arrow drops in and manages to catch Nyssa with a rope arrow, but the assassins still get away with Malcolm. Nyssa says that's the last they'll ever see of him.
Ollie takes Nyssa to the Arrowcave and puts her in this tiny little cage that I think is supposed to be for a dog. Ollie tells everyone to clear out of the room, which makes them all think he's going to torture her. Instead, he straight-up asks her where Nanda Parbat is, and she immediately tells him, because he has abetted Sara's killer, so she knows Ollie is going to die there, too.
Harbinger tells Dig that he should go with Ollie to face down Ra's, so Dig asks for the ARGUS jet. Meanwhile, Thea literally begs Ollie not to go to Nanda Parbat on what is essentially a suicide mission. While the guilt of killing her father might be bad, her brother dying on her behalf is worse. Ollie smirks while cavalierly saying he's going to go. The nerve of this guy.
In Nanda Parbat, Malcolm gets dragged in front of Ra's. He tries to cut a deal, then begs for his life, but Ra's says Malcolm's got to pay for what he did. If it's any consolation, Ra's says, he won't enjoy it.
Dig and Ollie show up at Nanda Parbat dressed up as cartoon thieves. They should be carrying giant sacks with dollar signs drawn on them. Also cartoon-like, the minute Ollie mentions the element of surprise, assassins start raining arrows down on him and Dig, but they miss wildly. Dig pulls out a gun and straight-up starts shooting dudes, and Ollie starts blasting fire arrows at people. I'm pretty sure they're both killing guys.
The two of them get inside and find Malcolm with the help of a tracker. Just as Malcolm starts to get out the word "trap," a gate closes behind them.