Back in Starling City, the hunt continues for the boomerang wielding madman and Oliver has tracked him to a house in the city. Oliver, Roy and Diggle all get in position, but the house is rigged to blow. Thinking on their feet our esteemed archers blow the charges and enter, but there’s no sign of the killer. There is, however, a team of ARGUS agents with guns pointed at Oliver and Roy. They pair quickly figure out that the man killed by the boomerang was an ARGUS agent, and when told to let it go by the agents Oliver decides to do anything but. At Arrow HQ the team learns more about the former ARGUS agent-turned-murder victim and Diggle says he’ll do his best to get info from Lyla.
Flashing back to Hong Kong (Who’d have thought we’d get these during the crossover!) and Amanda Waller has called in Oliver to get information out of a man who has placed bombs around the city. She even brought him a present: his bow and arrows. In the present day, and at Palmer Tech, Felicity gets ready for work when she is visited by Caitlin and Cisco from Central City! They want to help her with the boomerang case, and also see the Arrow Cave, which they apparently do not call by that name (sorry Oliver). Inside, Cisco is playing with the trick arrows much to Oliver’s chagrin, but not to worry he’s got some ideas too.
At ARGUS HQ Diggle tries to convince Lyla to throw him a bone and let them handle the boomerang man, who just so happens to be entering the building with the dead agent’s ID. He starts killing agents ala the hallway scene in Oldboy albeit with boomerangs and it seems like ARGUS is about to have to hire a bunch of new employees. Diggle calls Oliver and Roy who make it just in time to fight the killer, but just when the boomerangs get the drop on Oliver, our favorite speedster enters the picture and saves him. As Barry speeds off, and Lyla asks what that was, Oliver asks for more info on the killer who she reveals to be Digger Harkness, a former member of the Suicide Squad whose implant malfunctioned. They decide ARGUS has been compromised and they should bring her to the Arrow Cave (I can’t help myself).
Barry works up an appetite performing on Oliver’s salmon ladder and darts off to get sushi as Oliver and company (heyo!) enter the Arrow Cave. To the surprise of everyone, especially Lyla, Barry pops back in where he learns what happens when you assume. Oliver pulls Barry aside and says thanks but no thanks, but changes his mind when Barry agrees to do things his way. As all of the smartest people in the world (sans the creep Dr. Wells) figure out Harkness’ boomerangs, they deduce they were 3D printed and infused with C4 charges. They’re also somehow able to figure out who made them (Klaus Markos) and upon further review learn he was arrested just one year ago by Quentin Lance.
Oliver takes Barry over to SCPD to meet Captain Lance, who isn’t much help besides revealing that Markos was arrested for identity theft and that he works for Oliver’s old friends the Russian Mob. There’s also a brief moment where Laurel chastises Oliver for appearing as the Arrow in Central City, it’s cute. After casing the Russian mob hideout, Barry runs in and ties up all the goons leaving just Markos untethered inside. He grabs him and Oliver pops an arrow inside his shoulder, twisting it around to get some info only to have a cell phone linking them right to Harkness handed over. Barry transports Markos directly to Lance’s office, handcuffing him to a filing cabinet, and then he goes to have a talk with Oliver about his methods. Oliver reminds Barry he agreed to do things his way and he’s free to go if he wants.
At the Arrow Cave Lyla can sense the tension between Oliver and Barry and the two ponder how often they butt heads with others over their differing world views. She even namedrops the title of the episode (“The Brave and The Bold”) during her insight. Felicity has tracked Harkness to a warehouse in town at the corner of Infantino and Adams (A very clever Easter Egg as it refers to Carmine Infantino, co-creator of Barry Allen, and Neal Adams, an artist on the Green Lantern/Green Arrow stories printed in the back of The Flash, and the streets are literally crossing over. Get it?). Oliver puts Cisco with Roy and Diggle in the van and Barry agrees to play by Oliver’s rules. Once again we return to Hong Kong, where Oliver is getting ready to torture his new friend, or maybe not since he clearly doesn’t want to do it and even the victim can see this. Just as Oliver works up the nerve to do something, the bombs go off.
As Cisco, Diggle, and Roy drive to the place (and Barry speeds past them) they talk about the heroes and meta-humans in the world. Cisco thinks they’re a blessing, a tool to use against “the crazies.” Roy and Diggle seem to not have thought about this one. Oliver enters the warehouse but Barry has already tied everyone up, well, almost everyone, whom Oliver takes out with an arrow. The thugs inside reveal they don’t know who Digger Harkness is but he paid them to give a cell phone to the Arrow, which they do. Meanwhile at the Arrow Cave, Harkness is inside (they should really get a security system) and starts throwing his favorite toys. Try as she might to defend herself, Lyla takes a boomerang to the chest and stops breathing. The team gathers back at HQ and they have Barry carry her to Starling General Hospital.
Oliver wanders through the rubble and aftermath of the bomb in Hong Kong where he’s met by Waller who paraphrases the late Johnny Cash and tells him to get tough or die. “Torture is an art” she tells him, and Oliver has the tools to carry it out. As Cisco, Caitlin, Roy, and Felicity grab drinks topside, Lyla heads into surgery, and Oliver decides to take a trip to mope-town and blame himself for everything, citing how much he has lost his humanity. Barry isn’t buying it and tells him he still has humanity or he wouldn’t have gotten where he is. Felicity pops in to tell them she’s got a hit on Harkness, who is getting ready to board a train.
Barry clears out all the passengers from the train station and our two heroes stare down Captain Boomerang. Harkness reveals that he has a contingency plan – five bombs scattered across Starling City. They can stop him or the bombs, their choice. Oliver throws down with Harkness as Barry races to the bomb sites, which Felicity and Cisco are able to track via radio waves or something. Felicity tells Barry he can’t disarm one bomb without the other four detonating, so he’ll have to defuse them all at once. This gives Barry the genius plan to take his four friends and place them all at the bombs where they will diffuse them at the same time. He races back to the train station where Oliver has strung up Harkness by his neck, and when he tries to grab a boomerang Oliver sticks him through the hand.
Lyla wakes up in the hospital where Diggle mans up and asks her to marry him (again), which she agrees to. At the Arrow Cave, Caitlin tells Felicity she’ll work on the DNA from the arrows that killed Sara – she’s got nifty DNA software to fill in the holes (like Jurassic Park!). Barry and Oliver enter and drop that Harkness and Slade Wilson are now roommates on Lian Yu, a sitcom that I want to see. As everyone gets ready to leave, Barry sees that they’ve installed a fancy mannequin for his own costume in the Arrow Cave, “For Next Time,” and Cisco presents Oliver with a new outfit, but first they have unfinished business.
In our final Hong Kong flashback of the episode, Waller calls in Oliver one more time to practice his torturing skills, and this time the target is someone with information on China White. Oliver gets his arrows ready to go to work as we fade out. Barry and Oliver walk together in an empty warehouse to settle it once and for all, after all things were “a tie” during last night’s episode. They toss out the usual fanboy arguments, which is pretty hilarious. Barry’s got powers but Oliver’s got tactics and training. Who will win? We don’t know because they cut to black just as things are about to get interesting.