Crisis on Infinite Earths: Part Four

"You have failed this universe!"

- Oliver Queen to the Anti-Monitor

The episode is the fourth part of the five-part crossover, ​.

Starring

 * Stephen Amell as Oliver Queen/The Hood/Green Arrow/Spectre
 * David Ramsey as John Diggle
 * LaMonica Garrett as Mar Novu and Mobius/Anti-Monitor
 * LaMonica Garrett as Mar Novu and Mobius/Anti-Monitor
 * LaMonica Garrett as Mar Novu and Mobius/Anti-Monitor
 * LaMonica Garrett as Mar Novu and Mobius/Anti-Monitor
 * LaMonica Garrett as Mar Novu and Mobius/Anti-Monitor
 * LaMonica Garrett as Mar Novu and Mobius/Anti-Monitor

Special appearance by

 * Katie Cassidy as Laurel Lance
 * Jon Cryer as Lex Luthor
 * Ezra Miller as Barry Allen

Special guest star

 * Grant Gustin as Barry Allen/The Flash
 * Caity Lotz as Sara Lance/The Canary/White Canary
 * Brandon Routh as Dr. Ray Palmer
 * Tyler Hoechlin as Superman and Dr. John Deegan/Superman
 * David Harewood as J'onn J'onzz/Martian Manhunter
 * Elizabeth Tulloch as Lois Lane
 * Ruby Rose as Kate Kane/Batwoman
 * Melissa Benoist as Kara Danvers/Supergirl

Guest starring

 * Osric Chau as Dr. Ryan Choi
 * Stephen Lobo as Jim Corrigan
 * Melanie Merkosky as Xneen

Uncredited

 * Katrina Law as
 * Manu Bennett as
 * Matt Nable as
 * Neal McDonough as

Plot
Maltus - 10,000 Years Ago... Mar Novu is bantering with his wife Xneen as he suits up and is getting ready to travel to the dawn of time. He affectionately calls her The Monitor as she's monitoring his time travel. He steps into the portal and arrives at the dawn of time but something goes horribly awry as antimatter begins to corrupt the temporal zone. A hole in the universe is subsequently created, and Mar Novu ends up being sent to a different universe all together, the anti-universe in fact, which results in the creation of the Anti-Monitor.

Through the speaker comms, he apologizes to his wife, saying that because of his ambition, he has subsequently doomed them all.

Vanishing Point Months have passed, and The Paragons are struggling with the stark reality of their situation; that everyone, save for them, is dead. Ryan Choi writes a letter to his now deceased wife, to give him some semblance of comfort. He explains how he just don't see why he was chosen as paragon. He then goes on to explain how "the so-called Paragon of Destiny doesn't even believe in tomorrow anymore. That the Paragon of Courage spends everydays working herself to the bone, training for a fight that will never come. Then there's the Paragon of Honor, who just meditates, for hours and hours on end. Dr. Choi goes further writes that the Paragon of Hope has lost hers, and as for him, he spends his days trying to re-purpose the broken technology lying around this place trying in vain to find a way out. In his letter, he doesn't have the nicest things to say about Lex Luthor, who used the Book of Destiny to rewrite reality and take the place of Clark Kent (Earth-96), the real Paragon of Truth. Ryan goes onto say that there are a lot of ways to describe Lex Luthor...But that he personally finds douchebag to be the most descriptive. He finishes his letter by saying that as for Barry Allen, AKA The Flash, AKA the Paragon of Love is just gone. Missing.

Lex and Ryan reveal to the other Paragons that they have come up with a teleportation device and Supergirl volunteers Lex to try it out, but it doesn't work. Lex admits that it was a long shot anyway.

Shortly thereafter, Barry reappears, and looks to be a bit disoriented. Kate tells him that he has been gone for months. Barry is shocked to learn that, because to him he had just left them two seconds ago. He tells them that there's no way of here, and that not even the Speed Force can get them out.

Purgatory Oliver is still with Jim Corrigan, the current Spectre as he relives the fights with some of his greatest foes, which include Malcolm Merlyn, Ra's al Ghul and Damien Darhk. Oliver's eyes flash a bright emerald green, and a moment later, Jim asks him what he saw. Oliver answers that he sees everything.

Jim explains that every punch Oliver threw, every kick he landed, and every arrow he fired all led him here, to this very moment. The ultimate fight. He goes onto explain that the Anti-Monitor is more than just The Monitor's adversary, but rather, is the being that stands between all that ever was and all that ever will be. Jim describes the Anti-Monitor as the apocalypse itself given life and form, and terrible purpose.

He goes onto tell Oliver that he can defeat the Anti-Monitor, but only if he has some help on his side, and the two go get the Paragons.

Vanishing Point Kara is telling Barry that he needs to rest since he's not looking too good, but the distraught scarlet speedster says that he can't, and that he needs to try going into the Speed Force again. Sara then tells Barry that it's a bad idea, and that the effort alone could kill him. Barry refuses to listen to the other, and says that anything is better than just staying here in the Vanishing Point.

Kate also interjects, and says that they're not going to let him kill himself, but a distraught Barry tells her to get out of his way.

Sarah doesn't budge, and tells Barry that they aren't letting him go anywhere in the condition that he is currently in and manages to physically push him back.

An angry Barry, taunts Sara, asking her to try and stop him, to which Sara replies that in the current condition he is in, it wouldn't be that hard.

Unable to take the fighting any longer, Kara tells the two other heroes to cut it out, because whatever is going to happen, won't include them turning on each other.

Kara tries to reason with Barry, saying that maybe, just maybe the Speed Force is their last hope.

Oliver then shows up at the Vanishing Point and reveals that the Speed Force is, in fact, the key to saving everyone.

The heroes are surprised to see Oliver and he explains his new situation as Spectre after Sara says "Oliver?" to which he replies by saying, "Yes and no. It's complicated." He explains that he is Oliver Queen, but has also become something more. When Barry asks for clarification, Oliver replies by saying that some may call him a ghost or a spectre that is attuned to the entire multiverse.

He also confirms that the Multiverse is gone and the antimatter universe waits to replace it. Oliver reveals to the Paragons that the Anti-Monitor is at the dawn of time trying to make his antimatter universe permanent, and that they need to go and stop him.

He warns the Paragons that the Anti-Monitor is extremely powerful and that the eight of them might not be enough to put a stop to him. Thus, they need a back up plan, which turns out to be that they need to split up. Some of them will go to the dawn of time, while the other will go to Maltus, to try and stop Mar Novu from unintentionally creating the breach that started it all from ever happening in the first place.

Barry asks Oliver that if being attuned to the entire multiverse also includes him being attuned to the Speed Force. Olives says yes, but warns Barry that it's very dangerous. But Barry tells his friends that he needs a boost because everyone’s lives depend on them. Oliver touches Barry's forehead, and says that it's done, but that he needs to use this newfound power with caution.

Oliver asks Barry if he trusts him, to which Barry asks him if he really is Oliver Queen. Oliver answers by simply saying yes. So Barry nods, and says he trusts Oliver with every cell of his body.

Oliver then tells Barry to run, and he subsequently goes into the Speed Force.

Maltus Kara, Ryan and Lex end up on Maltus, and she tells Ryan to focus, when he wonders why the alien planet doesn't look alien enough.

Kara says they need to look for Mar Novu, and it’s not like they can do an internet search on him.

Ryan says that maybe they can and points to the city in the distance. He goes on to say that any city that large has to  be a bureaucracy, and bureaucracies require some form of central data bank to function. So if they find that, they find Mar Novu.

Around that same time Ryan is coming up with a plan to find Mar Novu, Lex vanishes.

Inside the Speed Force Elsewhere, as Barry is running through the Speed Force, the Anti-Monitor hand is reaching through it, and looks to be close to catching Barry. But he narrowly manages to avoid being caught. However, Barry gets separated from Oliver and the other Paragons and runs headlong into some boxes.

Once he takes a closer look, he finds the Queen Consolidated logo on them, and hears his the echo of his own voice apologizing to Oliver, Felicity and the others for being late.

He then sees Oliver, who is now wearing a suit, and tells Barry that he is still in the Speed Force. Oliver explains that the Anti-Monitor attacked them, and as result, they all got separated. He adds that this includes him too, and that he's somewhere in the Speed Force as well, using various pieces of his essence to keep himself, Sara, J'onn together.

Oliver also adds that there are fewer things more powerful in the universe than memory and connection. So he's using their memories of their friends and closest allies to keep all of them from falling out of the Speed Force. Because if they do fall out of the Speed Force, they will be consumed by antimatter like everyone else before them.

Oliver explains that he can buy Barry time but that he needs to get to each of them before it's too late. Barry argues that the Speed Force is infinite, and he wouldn't know where to look.

Oliver tells him before he disappears, to remember what he just said about memories and connections. He goes on to say that he needs to take into account their greatest victories, their most crushing defeats, and the moments when the bonds between them were forged.

Barry runs and ends up in S.T.A.R. Labs, where he meets another Barry Allen who doesn't seem to know anything about the Speed Force or isn't even calling himself The Flash yet.

The other Flash asks what the hell is this, and the Flash from Earth-1 says he's asking himself the same question. Earth-1 Barry says that this can't be happening, and asks the other Flash what he's doing here. The other Flash tells him that he'll tell him that when Earth-1 Barry tells him where here is.

He asks The Flash from Earth-1 if this is his cosplay and asks him if he wants a selfie. Barry says no, that he's The Flash, but the other Barry Allen has no idea what Earth-1 Barry is even talking about.

Earth-1 Barry says it's complicated. The other Flash tells Earth-1 Flash that he likes his outfit and that it looks very comfy. Earth-1 Barry tells the other Flash, he likes his suit too and says that it seems safe and cool. Amazed,the other Flash says that Earth-1 Flash's outfit looks very breathable.

They then introduce themselves and both say they're Barry Allen. The other Barry asks what does that even mean. Whereas Earth-1 Barry says that this should be impossible now. He then begins to ask the other, Barry if he doesn't know about the...But ends up not finishing that sentence. The other Barry pleads with Earth-1 Barry to not do this to him. But then he begins to disappear, as he says that he told Victor this was possible.

Maltus Back on the Planet Maltus, Kara finally catches up with Lex, and asks him what he is doing.

He replies by saying that he's doing what she should have done from the get-go; getting the lay of the land, and that he's looking for any potential hidden dangers because they’re in an alien world and that any number of predators could be waiting to pounce.

Lex then asks Kara if either her or Superman have ever even watched a movie to know this common sense stuff.

Kara warns Lex that she will figure out whatever he's planning and stop him. Lex says he highly doubts that because in a contest of mind and muscle, the mind wins every time.

He tells Kara to ask him what he's up to, she acquiesces and asks him just that, to which he replies that he’s after universal domination and blasts her; thus knocking her out. He mentions that he probably should have mentioned that he gave himself some upgrades when he looked at the Book of Destiny.

Inside the Speed Force Meanwhile Kate finds herself in a memory of Oliver at Palmer Technologies, where the man in question is telling Ray Palmer, that he didn't kill those people. Oliver then turns around after telling Ray he has no idea what he's up against, and notices Kate; immediately asking her who she is.

In another memory inside the Speed Force, a TV screen is showing the Dominators on Earth-1, and the headline for the Channel 52 news reads, "Invasion! Extraterrestrials Attack Earth". J'onn J'onzz finds himself in the memory where Oliver finds out about a multiverse existing and meeting Kara for the first time. The two are not off to a good start, but J'onn tells the Kara and Oliver he sees about the Anti-Monitor, and how eventually they will be close friends.

Maltus Back on the Planet Maltus again, Ryan Choi wakes up after also being knocked out by Lex and checks up on Supergirl. She in turn checks him for injuries with her x-ray vision and says he'll be fine as she didn't see any broken bones. The two paragons then talk about how Lex is such an asshat, and that knowing him, Kara thinks he will likely mess with Mar Novu's experiments to alter history to his advantage. She then stops midway, and asks Ryan if he has ever flown on an alien planet, Ryan says he never has flown period. Kara tells him to not be nervous, that it’s just up, up, and away!

Inside the Speed Force Barry continues working his way around looking for Oliver and the other paragons, and in turn ends ups in a moment that he, Barry, didn't participate in. He approaches Oliver, who remembers everything. Barry confronts Oliver and asks him why he made a devil's bargain with the Monitor the year before. Oliver disagrees, and says it wasn't a devil's bargain, and that he'd make the same choice again in a heartbeat. Barry says that in choosing to save him and Kara from dying in this crisis, he lost his family and his life in the process.

Oliver tells his friend that, "dying is the easy part, the dead are at peace. The real heroes are the ones who have to keep going".

Still in the Speed Force, Barry then finds himself interrupting Laurel Lance and John Diggle talking about the Canary legacy by Sara's dead body. Barry touches Sara's corpse and she wakes up; with Laurel saying it's a miracle but Barry whisks Sara away. At a much faster rate, he collects J'onn, and then Kate from the where they were in the Speed Force.

Maltus Lex shows up as Mar is about to make his jump and tries to team up with him for his own benefit, explaining what goes wrong, but then Supergirl shows up. Ryan gets Mar out of the way so that Supergirl and Lex can fight. Ryan tries to convince Mar that he can't open the portal, pleading with him. On their way out, Mar Novu sees his wife unconscious on the floor. Ryan manages to convince Mar Novu not to go through with his experiment as the cost would be too great.

He then tells Kara and Lex they need to stop fighting, and Lex remarks how Ryan just ruined a perfectly good bad guy plan. The 7 paragons and Oliver then end up on the antimatter universe, home of the Anti-Monitor after Barry whisked them all there.

Ryan says it's impossible that they arrived here, because he knows he got through Mar Novu, and he didn't go through with the experiment. However, the Anti-Monitor is already there waiting for them. The Anti-Monitor tells the Paragons that some fates are inescapable, that they may have stopped one version of Mar Novu from going through the experiment, but that another version of him did go through with. He then begins to unleash his army of Shadow demons.

Oliver then shows up, and tells them to listen to him, that this is why they were selected as Paragons. When Ryan says he's still unclear on what that all means, Oliver answers that it means they are all powerful enough to hold the line; to buy them the time they need to rebirth the universe. He explains that the dawn of time is the only place where this do over can happen. He goes onto say that he will light the spark, but they need to fan the flame. When Lex asks how they will do that, Oliver replies that Lex'll know when it's time.

The Anti-Monitor tells Oliver that it's too late and that after 10, 000 years he will finally be victorious. Oliver says that no he won't win, and that he believes his entire life has prepared him for this fight. The Anti Monitor says that all life ends, and that only death is eternal.

When he says that only he is eternal, Oliver takes off his hood, and tells the Anti-Monitor that "we'll see about that."

Oliver and the Anti-Monitor engage in a fight, and as they're fighting, Oliver tells hims that he has failed this universe and unleashes a surge of power.

Their clash provided the spark, and it was up to the Paragons to fan the flame. They focused on Hope, Destiny, Humanity, Love, Truth, Courage, and Honor. The resulting blast makes the Anti-Monitor disappear. With Oliver dying, Barry brings Sara to him, and he makes both of them promise to watch over his family, as he passes away.

Above them, the new universe grew as Oliver died; finally at peace.

Production

 * Production for began on September 24, 2019.
 * Filming for the crossover had completed by November 8, 2019, with some reshoots and minor filming still needing to be completed.

Trivia

 * This is the first episode of the series to not feature  and after being promoted to series regulars.
 * The part of the  crossover was co-written by Marv Wolfman, who co-wrote the original Crisis on Infinite Earths comic in addition to co-creating the characters who made their debut in the novel including Harbinger, The Monitor, Pariah and the Anti-Monitor.
 * This part along with both aired on Grant Gustin's 30th birthday.
 * In the comics, Maltus is a planet whose inhabitants, the Maltusians, are race of beings that include the Guardians of the Universe, the Controllers, Krona and the Zamarons. They are most affiliated with the Green Lantern Corps.
 * When Oliver Queen appears as the Spectre, Ryan Choi compliments the cloaked figure, saying "Very Sith" referencing the Star Wars franchise.
 * To gain the heroes' trust, Oliver tells Barry "Run, Barry, Run." This has been said to Barry several occasions throughout the and  series, including from Oliver himself on
 * While DC Extended Universe films is not impacted by The CW's Arrowverse, Ezra Miller's version of Barry Allen did make a brief appearance in this episode.
 * However this is the first time Ezra Miller's version of Barry Allen is called the Flash. Making it possible it might affect his universe in future films involving him.
 * This marks the first time that the DCEU Films and Arrowverse have crossed over.
 * When the Paragons are spread out throughout the Speed Force, they are sent to past events in the Arrowverse including:
 * The first time Oliver and Barry met in the episode,.
 * J'onn lands at the time of the crossover, specifically.
 * The crossover, specifically, during the final battle against John Deegan.
 * Sara ends up at the point when Diggle and Laurel talked about the Canary legacy by Sara's dead body in (with Barry then showing up and bringing her body back to life).
 * Kate ends up at the time when Ray and Oliver talk about Oliver being the Arrow in.
 * That scene was not supposed to be for Kate. Originally, she was going to break up the fight between Oliver and Diggle in.
 * Chronologically this is the final time Oliver says "You have failed this..."
 * Oliver tells the Paragons that he's in tune with the entire multiverse, and Barry says that must mean that Oliver can give him the energy boost he'd need to get into the Speed Force. Oliver then responds that what Barry's asking is very dangerous, but Barry insists that they need to do it because everyone's lives depend on it. Barry would come to deal with the consequences of this choice later in back half of The Flash season 6, but wouldn't begin to realize the gravity of what had happened until.
 * Oliver's quote about death is similar to what Harry Wells said in, "Everyone loses someone they care about, Snow. The real test of character is what you do once they're gone."
 * This is the only episode in the Arrowverse to not primarily take place in either the original multiverse or the new multiverse.
 * This is the final episode to feature Katie Cassidy portraying Earth-1 Laurel in any capacity.


 * Lex voices annoyance at how "cosmic types are obtuse" with explaining things. A callback to how viewers get annoyed with higher powered beings never being direct with their words.

Goofs

 * Before Barry ran himself and Sara over to Oliver, his mask was on. However, it is off when he arrives.