When the first half of "The Flash"/"Arrow" crossover concluded yesterday, it left two huge questions: is Oliver a father, and can both teams defeat Vandal Savage? Both of those questions are answered on tonight's episode of "Arrow" titled "Legends of Yesterday."
When the episode starts, Kendra (Ciara Renee) is remembering her past. In her vision, she can see herself as Shiera, a priestess in the court of Ramses. She is making an offering to the Egyptian god Horus with Ramses's son, Prince Khufu (Falk Hentschel.) Their offering is interrupted by Vandal Savage (Casper Crump), who says that the celestial rocks (meteors) will keep falling as long as Horus in unappeased. When Kendra wakes up from her vision, she and Carter, along with the rest of both Team Flash and Team Arrow -- Barry (Grant Gustin,) Oliver (Stephen Amell,) Felicity (Emily Bett Rickards,) Cisco (Carlos Valdes,) Caitlin (Danielle Panabaker,) Thea (Willa Holland,) Laurel (Katie Cassidy,) and Diggle (David Ramsey,) -- arrive at a secluded farm house outside of both Star and Central City. Thea cracks a joke about superheroes taking refuge at a farm house, which may be the first time this DC Comics-based show has made a reference to a Marvel property. (In this case, "Avengers: Age of Ultron," -- remember Hawkeye's secret farm?)
Felicity, Cisco, and Caitlin begin working on special gantlets that can withstand the power of Savage's staff, which inspires Oliver to lovingly call them the "Geek Squad." Another reason these crossover episode are awesome: watching Cisco, Felicity and Caitlin geek out and science the heck out of problems is the best.
While the rest of the team starts researching Savage and working on the gantlets, Oliver takes this opportunity to do some digging on his potential son, and Kendra and Carter begin training. Kendra doesn't take to her trailing very well, until Carter shows her the Hawkgirl costume. According to him, when her memories come back, so will her powers, which include her fighting skills. Carter even tests her language skills, which may come in handy over on "DC's Legends of Tomorrow." Oliver finds out where Samantha Clayton (Anna Hopkins) lives and questions her about her son. Sandra swears that her son -- William -- isn't Oliver's son, but Oliver takes a piece of his hair anyway, so he can run a paternity test on it later on.
While at Sandra's, Oliver gets a call from Malcolm Merlyn (John Barrowman) who has arranged a meeting with Savage. Oliver and Barry agree to meet with Savage, but while Barry is running to the meeting, something very interesting happens: he sees himself in a speed mirage. The last time this happened was in "The Flash" episode 15, "Out of Time," where Barry had to use his speed to go back in time to prevent the death of everyone in Central City. When Barry arrives at the meeting with Savage he doesn't tell Oliver about the speed mirage, but he does tell Cisco when he gets back to the farm house later. At the meeting, Savage threatens to annihilate both Central and Star City if Oliver and Barry do not turn over Hawkgirl and Hawkman. Merlyn urges them to comply, as two lives are not worth the lives to two entire cities. Even though Merlyn should be used to Oliver's heroic optimism by now, he does not hesitate to deliver a terrifying death threat, saying that if any harm comes to Thea, Merlyn will come at Oliver with everything he has. This feels like a set up for a future Merlyn vs. Oliver battle, and possibly a clue as to who is in the grave in the winter finale. If Thea dies, Merlyn will let all hell break loose in the second of half of "Arrow's" season four -- but that's just speculation for now.
Back at the farm house, Oliver lets Kendra and Carter know that Savage wants them delivered to him in 24 hours. Carter says Savage has decimated entire cities before trying to get to them. With Savage's life force tethered to their deaths, he'll go to any lengths to kill them. Kendra doesn't think her life is worth the death of millions, and Carter tries to talk her out of killing herself. Carter initiates a training session -- "Mr. and Mrs. Smith" style -- to get Kendra to awaken the warrior rage within her. While Carter and Kendra work out their feelings on the issue, Barry tells Cisco about the speed mirage. Cisco doesn't want to know anything about it and even throws out the "Fight Club" time travel rules, "The first rule of time travel is, we don't take about time travel." Cisco really doesn't want to know anything because the last time Barry time traveled, Cisco ended up dead.
Laurel, Thea and Diggle turn up with some interesting information about Savage when Diggle finds an old Betamax tape from A.R.G.U.S. The tape is a recording of professor Aldus Boardman (Peter Francis James.) CBR reported on his casting in September, and his presence in the episode is a huge connection to the upcoming spinoff, "Legends of Tomorrow." His video is recorded on April 8, 1975, and judging from what we already know about the "Legends" time travel storylines, it's possible we will see him record this video on a future episode of the show, possibly in a "Doctor Who"/"Blink" way where Kendra and Carter tell him he has to record it so they can see it in the future. In the video, Boardman warns that Savage will be the death of the world, but that there is a way to stop him: by using some of the metal that fell back in the time when Savage first gained his powers. Later on these metals are revealed to have fallen from a meteorite that fell on Savage, Carter and Kendra back in Egypt. In the comics, this metal is known as Nth Metal, which is tied directly to Hawkman and Hawkwoman's origin stories. If this metal can stop Savage in this crossover episode, will it also stop him in "Legends of Tomorrow?"
While the team continues to work on their plan to take Savage down, Barry runs a paternity test for Oliver and discovers that Oliver really is William's father. Felicity finds out too, but not before Oliver pays young William and Samantha a visit. Samantha comes clean about Moira trying to pay her off years ago, and agrees to let Oliver visit William, if he doesn't tell anyone about William being his son. Oliver gets to meet William, who is very sweetly playing with action figures of The Flash and Captain Cold. Later, when Felicity confronts Oliver, he lies, and this forces Felicity to give Oliver a very painful ultimatum: come clean or break up.
The episode wraps up with a crazy series of events: Barry and Oliver take Kendra and Carter to Savage, pretending to turn them over, but when the time comes to take Savage down, Kendra can't tap into her powers, the gantlets don't work, and Savage literally kills and destroys every single person on Team Arrow and Team Flash. Barry is the only person able to run away from the blast radius. Thankfully he knows how to tap into the time travel speed force and is able to run all the way back to his original meeting with Savage. When the meeting is over, for the second time, Barry tells Oliver about the time travel. He doesn't go into the details, but he urges Oliver to do things differently. This time Oliver doesn't go into the fight alone: he takes his whole team, including Laurel, Diggle, and Thea, who roll in on Savage like gang busters. Felicity never finds out about Oliver's son, and Oliver agrees to keep Samantha's secret. Kendra is able to tap into her powers because Cisco is able to help her tap into who she really is: a hero. When Kendra flashes back a final time, her initial history with Savage and Carter is revealed. When she sees the staff and the Nth metal she understands what must happen to beat him. Barry finds another meteorite that is made out of the same Nth metal and Cisco coats the gantlets with it.
The team then goes all in together, and in an epic tag team fight, they disarm Savage of his staff and turn him into dust. The final moments of the episode reveal Malcolm Merlyn gathering Savage's ashes, repeating the same oath of vengeance. As Merlyn collects the ash, he tells Savage that he "owes him one." Nothing good can come from Savage owing Merlyn, especially considering Merlyn's previous threat to Oliver earlier in the episode. Barry also warns Oliver about the effects of changing the time line, which could be what puts someone in the ground in next week's winter finale. Lastly, Cisco and Kendra say goodbye, but not before Cisco can give her a belt made out of the Nth metal. In the comics, this belt is very significant, and will definitely be seen again in the upcoming spinoff, "Legends of Tomorrow."