A week may have passed in the TV world, but we only had to wait a day after The Flash‘s fantastic “Flash vs. Arrow” crossover to get another team-up between Barry Allen and Oliver Queen, this time in Starling City, which is pretty much the most dangerous place in the world, it seems. Barry and the Flash Gang aren’t used to all the death and destruction that happens when non-Metahumans (known colloquially as “humans”) do awful things to each other. It’s kind of a thing they do a lot.

For whatever reason, it felt like The Flash folks being on Arrow fit better than Arrow people being on The Flash, though I’m not entirely sure why. And, of course, there are way more characters on Arrow so once again people like Thea, Laurel, and Captain Lance get pushed to the side. And where’s Malcolm Merlyn been these past few episodes? (We’ll find that out next week.) At any rate, Caitlin and Cisco interacting with “The Arrow Cave” as they insist on calling it is probably some of the funniest stuff in either show.

The flashbacks this week deal with Oliver being made to torture a guy by Amanda Waller in Hong Kong. We all know, and saw in The Flash on Tuesday, that Oliver is great at torturing guys to get the information he needs, but he wasn’t just a natural at it. His suspect knows where a bomb is planted and Oliver must use coercion to get the answer. But he doesn’t; he’s soft and thinks threatening the man with a bow and arrow will get him to talk. It doesn’t, the bomb goes off, and people die, which Waller holds over his head and makes him torture another guy better at the end. This all plays into Oliver’s big revelation.

We begin with the usual team of Arrow, Arsenal, and Diggle casing a location, this time being where they think the man with the deadly boomerangs is. After tripping both of his door bombs, they enter and find that ARGUS is also looking for the man, that it’s an internal matter, and Arrow should drop it. BUT HE WON’T! Meanwhile, Caitlin and Cisco come to Felicity’s office, nominally to give Ms. Smoak help with the blood sample, but really because they want to check out the Arrow Cave, which I’d like to remind everyone is what I’ve been calling it for years. Only me, surely.

Naturally, Cisco loves all the cool stuff and Caitlin is reserved. That’s their way. Roy seems confused as to why any of them would be allowed in here. Meanwhile, Diggle goes to ARGUS to talk to Lila about why they’d have a boomerang-toting crazy person on their to-find list, just as the man himself breaks in and starts tossing slicey boomerangs everywhere. Oliver and Roy jump to action, but the worry is it’ll take him too long to get there, so Caitlin calls ol’ red fast guy who arrives just as Oliver is about to get killed by boomerangs. Oh, gotta love The Flash.

Later, back at the Arrow Cave, Barry is zooming around like a crazy person and doing the salmon ladder way too fast, then runs out to get sushi, and returns just after the others come back. Lila had no idea who Barry was, so there’s another person with secret identity knowledge. Lila reveals that the man’s name is Digger Harkness, and was part of Task Force X…the Suicide Squad…and that a mission went tits up so Lila, filling in for Waller, made the call to have them all terminated, but Harkness’ neck-bomb didn’t go off. So that means, not only is Harkness alive and angry, but he blames Lila specifically.

After reconscructing the boomerang fragments, they determine that they could only have been made by a guy named Klaus Marcos, so Oliver and Barry go see Detective/Officer/Captain Lance who busted the guy a while back. This leads to Laurel’s one scene. Good for her. The Flash and the Arrow go pay Marcos a visit, and Flash subdues the goons there very quickly, and without too much violence, and Arrow uses his particular method to get information on Harkness, which includes stabbing the guy. He gives up a phone which Harkness gave him, but Barry’s very disturbed that Oliver would be capable of something so violent. Sometimes you have to do the difficult thing. Oliver tells Barry he’s not in Central City, where it’s sunny all the time and the bad guys have cute nicknames.

Later, Oliver and Lila bond over having to be the bad guy to do the right thing. She asks how he and Speedy are getting along and Oliver thinks she means Roy. It’s very funny. Felicity and Caitlin figure out where Digger’s hideout is thanks to the phone and Oliver and Barry head there, with Roy, Diggle, and Cisco in the van, where Cisco says he thinks people like Barry are what give regular folks hope. Sure. Barry again subdues goons quickly, but Harkness isn’t there, and moreover it was a trap. Harkness has used the phone to backtrace to the Arrow Cave where he begins attacking Lila, Felicity, and Caitlin. In the fight, Lila is struck in the chest and Felicity tosses a flash grenade which makes Boomerang flee.

Lila’s stable but she needs help, so Barry rushes her to the hospital. Later, Felicity, Roy, Caitlin, and Cisco sit in Verdant and drink their sorrows away. Caitlin and Cisco realize there’s a human price to all this superheroing, and real people can get hurt or killed.

Oliver, go figure, blames himself for all of this, and if he hadn’t tortured Marcos, he’d never have put Lila in danger. He says he’s been slowly trading away parts of Oliver Queen until all that’s left is the Arrow. Barry says he’s full of crap, and that it’s his humanity that helps him be the hero he has to be. He’s not all the way gone, yet.

Felicity eventually finds where Harkness is – the train station – and Oliver and Barry head there to have a final showdown. Barry removes all the other people so it’s a fair one-on-two fight. But Harkness has placed five bombs around the city that will go off in 90 seconds (REALLY!?!?!), so Barry has to run around and find them, but they all have to be cut at the same time, so he grabs Caitlin, Cisco, Felicity, and Roy to help him, while Oliver fights Harkness. This “90 seconds” lasts for about 5 minutes onscreen. TIME DILATION! Anyway, they do it, and Oliver shoots Harkness in the hand and he and Barry take him to Oliver’s prison on the island, to be cellmates with Slade Wilson.

Diggle finally re-proposes to Lila, who is okay in the hospital, and they can quit doing the “we’re not married” bit. Cisco gives Oliver a new suit that’s neater and stuff. And finally, just for the end, Oliver and Barry decide to go find out once and for all who’d win in a fight, but before they do that, Barry tells Oliver that he CAN inspire people. Not the Arrow, because the Arrow is a douche, but as regular ol’ Oliver Queen.

This is without a doubt one of the best episodes of the series, and I think it’s because the Flash team blended in so seamlessly with the Arrow team. It’s a fantastic 45 minutes of superheroism and, as I’m sure they will, they decided to cross the two shows over again, I’d be pretty okay with that. Maybe Joe West and Quentin Lance can have a whole episode of grizzled police guys doing something. That’d be all right.

Next week! Holy crap, you guys, it looks like the mid-season finale is going to be even more epic than this crossover. Oliver has to travel to wherever-the-hell and face off against one of the most dangerous men ever, the head of the League of Assassins, Ra’s al Ghul himself. Just take a look at the insanity.