Superman, Superman II, Superman III, Superman IV, Superman Returns, Crisis on Infinite Earths, Kingdom Come, the Smallville TV series, The Death of Superman, The Kingdom and The Dark Knight Returns.
Mia tells Sara, rather tensely, that Nyssa Al Ghul told her everything she needed to know about Sara. It's unclear why Mia would have a negative opinion of Sara then, as Nyssa was the one who dumped Sara and begged her to forget about her after she was imprisoned by the League of Assassins just before the Legends of Tomorrow were formed. (Perhaps Mia saw how the end of the relationship pained Nyssa and just assumed Sara had been responsible for hurting her favorite teacher.)
The entire scene in which baby Jonathan keeps interrupting The Monitor's dramatic speech and is passed down the line of heroes until eventually winding up with the Mick Rory of Earth-74 is a masterstroke of silent acting that tells you everything you need to know about all the heroes assembled by how they react. (Kate shrugging away from the baby, Kara's mortification that Jonathan doesn't seem to like her, etc.)
It's a delight to hear Wentworth Miller again as Leonard the snarky AI.
Brandon Routh stepped back into the role of Superman so naturally you'd think he'd been playing it for the past decade.
The set design for the dilapidated Wayne Manor on Earth-99 is amazing.
The scene in which Lois runs into the Clark Kent of Earth-96 is perfectly directed, acted and shot. The John Williams music is the icing on the cake.
While the idea of seven Paragons is unique to the Arrowverse Crisis, the number seven holds great significance in the DC Comics cosmology. There are seven forces making up the emotional spectrum that empowers the Lantern Corps, forming the white light of Life. There are seven members of the Endless. There are seven great enemies of Man whom Shazam battles. And there were seven founding members of the Justice League.
The Monitor makes reference to a book called the Tome of the Guardians, which gave him prophecies regarding the Paragons. This could be a nod to The Book of Oa - a book created by the Guardians of the Universe which records the history of the Green Lantern Corps as well as prophecies relating to them.
The exoskeleton which Kevin Conroy wears as the Bruce Wayne of Earth-99 is modeled on a similar device worn by Bruce Wayne in the 1996 graphic novel Kingdom Come.
Earth-99 seems to have been designated such as it is almost a total reversal of Earth-66. (i.e. The Adam West Batman reality). In that world, Batman is a recognized agent of the law who operates publicly and is well-respected and honorable. The Batman of Earth-99 is a vigilante feared by the police, who has no issue with killing his enemies.
Lex Luthor's plot to travel between realities with the Book of Destiny and kill as many Supermen as possible is similar to the plan enacted by Gog, the chief villain of The Kingdom - a follow-up to the original Kingdom Come. Angered after Superman rejected his attempts to establish a religion based around worshiping the Man of Steel, Gog went back in time and began killing Superman over and over, one day at a time.
As Mia is searching the remaining Earths for a Lazarus Pit, we see her flip past entries for Earth-33, Earth-92, Earth-67 And Earth-3 on the Waverider's computers. Nothing is known about any of these Earths except Earth-3, which is the home of the Arrowverse's Jay Garrick.
The Batman of Earth-99 is played by Kevin Conroy, who is famous for voiding Batman in many video games, animated movies and cartoons, including Batman: The Animated Series and the Arkham Trilogy. This is his first time playing Batman or Bruce Wayne in a live-action production.
When he first encounters Kate, the Bruce Wayne of Earth-99 presumes she must be a shapeshifter. He makes reference to the Clayface of his Earth being dead and says he knows for a fact Jane Doe is still in Arkham. First appearing in Arkham Asylum: Living Hell #1, Jane Doe is a serial killer with amazing impersonation skills who replaces her victims and lives their lives, hoping to find one that satisfies her.
The scene on Earth-75 in which we see Lois Lane hovering over the dead body of a fallen Superman, whose cape was torn and is flapping like a flag on a piece of rebar, is taken directly from The Death of Superman comics.
The reality of the TV show Smallville is designated as Earth-167. It was given this number because both of the show's executive producers - Alfred Gough and Miles Millar - were both born in 1967.
It is revealed that the Clark Kent and Lois Lane of Earth-167 have two daughters. This could be a nod to the story Superman: Secret Identity, where Lois and Clark had two daughters named Carol and Jane and Clark Kent also lost his powers to have a family.
Erica Durance and Tom Welling, who played Lois Lane and Clark Kent on Smallville, reprise their roles as the Lois and Clark of Earth-167.
Earth-96 is modeled on the first five Superman films (Superman 1-4 and Superman Returns) as well as the graphic novel Kingdom Come. Its designation comes from the year in which Kingdom Come was first published - 1996.
The Superman of Earth-96 is played by Brandon Routh, reprising his role from Superman Returns. Routh also appears as Dr. Raymond Palmer, whom he has portrayed on Arrow and Legends of Tomorrow for five years.
Kara's X-Ray vision confirms a secret passage to the Batcave his hidden behind the clock in Wayne Manor's library. This is a combination of the two most usual triggers for the Batcave's location in the comics and other media. Typically it is hidden behind a clock, whose hands are set to the time of Thomas and Martha Wayne's murders to open the hidden entrance. It is usually also located in the library, but sometimes the trigger is a book, a hidden switch on a chessboard or a button hidden inside a bust of Shakespeare.
The trophy case in Bruce Wayne's library on Earth-99 contains a number of familiar items; one of Joker's playing cards, The Riddler's cane, one of The Penguin's umbrellas, a snow globe that appears to be modeled on the one that Mr. Freeze had which depicted his ballerina wife in the Batman: The Animated Series episode Heart of Ice.
The Superman of Earth-96 describes how the Daily Planet staff were all killed by "a reject from Gotham... played what he called a practical joke and gassed the building." This is precisely how everyone in The Daily Planet was killed in Kingdom Come, when The Joker attacked the building.
There are a series of memorial plaques in Clark Kent's office listing those who died in the gas attack years earlier. They include a number of names of supporting characters from past Superman comics and movies.
John Williams' Superman score is used to undercut several scenes in The Daily Planet building.
The Earth-96 Superman jokingly notes, after being freed from Lex Luthor's mind-control, that "this is the second time I've gone nuts and fought myself." This is a reference to the events of Superman 3.
The Earth with an active Lazarus Pit discovered by John Constantine is Earth-18. In all of DC Comics' various cosmologies, Earth-18 has always been home to DC Comics' old west heroes like Jonah Hex and Bat Lash. It is presumably named after the 1800s.
Several of the lines said by the Bruce Wayne of Earth-99 after he learns that Kara is Supergirl are taken directly from The Dark Knight Returns. His exoskeleton is also revealed to have concealed Kryptonite, making it similar to the special armor Batman used to fight Superman in that story.
The Superman of Earth-96 says that Jonathan looks just like his son, Jason, at that age. Jason was the name of Superman and Lois Lane's son in Superman Returns.
John Constantine works a spell that allows him to search multiple Earths for a functioning Lazarus Pit.
(Kara is looking at a screen showing a model of how Earth-38 was erased from existence. Lex Luthor enters behind her. Kara is son enraptured she doesn't hear him until he speaks.)
Lex Luthor: An entire universe wiped from existence distilled down to a computer graphic. Got to say missing that wow factor.
Kara: Lena killed you.
Lex: (smugly) Yeah. Only for a little while.
(Kara pulls off her glasses and her eyes begin to low blue. Suddenly, The Monitor is there.)
The Monitor: Everyone has a part to play, even Lex Luthor.
Kara: You did this? You brought that poisonous snake back?
The Monitor: His destiny was unfulfilled. Lex Luthor still has an important role to play.
(Kate walks into the room in the middle of this conversation.)
Kara: So you can revive him, but you can't bring back Oliver? !
The Monitor: I restored Luthor long before the crisis caused my power to wane.
Kara: And what about those innocent lives on Earth-38? Did they not have destinies to fulfill? I'm sorry, but I can't trust a man who thinks Lex Luthor is an ally.
(Kara storms out of the room. Kate walks up to Lex and gets right in his face.
Kate: All I got from that is that if you die again that dude can't bring you back.
Lex (haughtily) And you are?
Kate: (menacingly) New. And unfriendly.
Sara: So I miss one group chat, and now there's Paragons, and I'm supposed to be one of them.
Mia: Yep, and Barry and I are gonna use a Lazarus Pit to bring my dad back.
Sara: Mia, it's not that simple. The Lazarus Pit isn't some magical mud bath where you get your soul and a cup of cucumber water at the end. You lose your humanity.
Mia: Nyssa told me everything I need to know about Lazarus Pits, and she told me everything I need to know about you.
Sara: Why don't you share your opinion when it's about your life?
Mia: Why don't you share your opinion when it's about your dad?
Kate: The Bruce I knew wore a different kind of suit.
Bruce Wayne-99: Lifetime of injuries, but you've aged well for a dead girl.
Kate: I died?
Bruce Wayne-99: 5 years ago.
Kate: Huh. Never been a ghost before.
Bruce Wayne-99:Hmm. Plenty of ghosts in this place, but you're not one of them. Clayface is a puddle of mud. And last I checked, Jane Doe was locked in Arkham. So who the hell are you?
Kate: (looking over Bruce's armor) Can you, uh can you sit in that thing? Because you're gonna need to for this.
(Sara pulls Constantine aside as Barry and Mia leave the room.)
Sara: We can't screw this up, okay? When we bring Oliver back, I need you to promise me you can bring back his soul.
Constantine: Yeah. One thing at a time, right, love?
Sara: I need to hear you say it.
Constantine: I'll do it.
Sara: Thank you.
Constantine: - to the best of my abilities.
(Sara sighs in annoyance.)
Clark Kent-167: Whoever you are, I'm just a guy working on his farm.
Lex Luthor: You will always be my greatest enemy on any Earth. It's written in the stars. And in this book, or I wouldn't know that on this Earth Clark Kent (chuckles to himself) is Superman. Where I come from, that would be ridiculous. He can't see past his glasses.
Clark Kent-167: Hmm. So what do you want?
Lex Luthor: Why, to kill you of course! And every version of you across the multiverse so that if the, uh, super friends somehow find a way to save existence there won't be a single Superman to stand in my way.
(Lex dramatically pulls out a sliver of green rock. Clark looks at it unimpressed and unpained.)
Clark Kent-167: That's Kryptonite. Which has no effect on me ever since I gave up my powers.
Lex Luthor: (incredulous) You gave up your powers?
Clark Kent-167: Can't say I've missed these chats.
Lex Luthor: You were basically a God! You could fly! You could see through walls! You had superstrength!
(Lex feels something crunch under his foot as he steps forward. He moves his foot, looks down and sees a toy car. Suddenly it clicks - this Superman gave up his powers to have a family.)
Lex Luthor: You're kidding me.
Clark Kent-167: That is worth more than any superpower.
Bruce Wayne-99: Clark always said yes to anyone with a badge or a flag. He gave them too much power. My parents taught me a very different lesson; life only makes sense if you force it to.
Kara: How much you care, how hard you try - those are the things that make you a hero; not powers or time travel. And you may not feel like you have the experience now, but you have the heart. You're one of the bravest people I know.
Kate: That Bruce was brave once, too, and he had heart. What if I end up like him?
Kara: You won't. You'll make your own destiny. I found this in his library.
(Kara hands the photo to Kate. It shows two teenage girls.)
Kate: That's Beth and me. From Earth-99. I wish I knew her like this.
Kara: Maybe you still can.
Kate: Sounds like the Paragon of Hope just got her hope back.
Kara: Ohh. Hope, help, and compassion for all. That's what I'm gonna do for Earth-38.
Kate: But Earth-38 is gone.
Kara: I know, but maybe I can use the Book of Destiny to bring it back.
Kate: The Monitor said that would be really dangerous, Kara.
Kara: I know what he said But what good is being the Paragon of Hope if I don't have any?
Harbinger says that John Diggle is at home with their son and that she is still finding the words to tell him that Oliver Queen died.
Sara apparently promised the rest of the Legends that they didn't have to do any more crossovers.
Harbinger recruits the Mick Rory of Earth-74 and that universe's version of The Waverider to act as a mobile base for the heroes fighting the Anti-Monitor.
It is said that the Legends of Tomorrow on Earth-74 retired after the death of one of their members. They abandoned the Waverider, except for Mick Rory, who turned it into a man-cave of sorts where he could work on his novels.
Like his Earth-1 counterpart, the Mick Rory of Earth-74 is a writer. He is not as successful, however, having completed only one novel which was self-published.
The Waverider of Earth-74 has an artificial intelligence named Leonard rather than Gideon, which bares the voice of Leonard Snart. It is unclear if this is a cosmic coincidence or if the AI was based on the personality of Earth-74's Len Snart after he died.
Leonard and the Mick Rory of Earth-74 do not get along at all.
Leonard's line to Harbinger about how he's "always pleased to meet a fan" is a nod to Captain Cold's reaction to being recognized by the metahuman criminals he helps escape custody in F122.
The Monitor went back in time and retrieved The Book of Destiny from a point before it was destroyed in Elseworlds. It told him of 7 Paragons - being of purest will who would prove to be the key to defeating the Anti-Monitor.
The Monitor identifies White Canary as the Paragon of Destiny and Supergirl as the Paragon of Hope.
The Monitor was only able to get vague descriptions of two of the other Paragons. The Paragon of Truth is a Kryptonian, who is said to have suffered a greater loss than most mortal men could endure. The Paragon of Courage is described only as "the Bat of the Future." and the path to them lies on Earth-99.
The Monitor says he has also been drawing information from a book called The Tome of the Guardians, which came into the care of Felicity Smoak.
The assembled heroes now know that Bruce Wayne is Batman on Earth-1.
Lex Luthor joins the heroes on the Waverider. Supergirl is less than happy about this and declares that she can't trust The Monitor if he thinks Luthor can be trusted to help them.
Kate asks Kara to come with her to Earth-99 to seek out that world's version of Bruce Wayne.
Apparently there is no Lex Luthor on Earth-1 as Kate Kane doesn't recognize the name.
Iris joins the team on The Waverider and tells Barry she will be helping Lois and Clark to locate the Paragon of Truth.
Barry says that he, Sara and Mia are working on finding a Lazarus Pit so they can resurrect Oliver.
Barry says that Oliver told him about how they Lazarus Pits were used to resurrect Sara and Thea Queen.
Mia tells Sara that she was told about the Lazarus Pits by Nyssa Al Ghul, who trained her to fight.
The Luke Fox of Earth-99 apparently lives in Wayne Manor and works for Bruce Wayne in an unspecified capacity. He is comfortable enough to answer the door without a shirt on.
The Bruce Wayne of Earth-99 has been retired from crimefighting for years and is only able to walk with the aid of a special exoskeleton.
The Kate Kane of Earth-99 died five years earlier. Apparently she also tried to step in and replace Batman after Bruce became too severely injured to fight properly.
Bruce makes reference to Clayface and Jane Doe when trying to confirm Kate's identity.
Constantine works a spell to find a working Lazarus Pit on Earth-18.
Constantine helped to work the spell that restored Sara Lance's soul in A405.
Iris, Clark and Lois travel to Smallville, Kansas on Earth-167 and warn that world's Clark Kent that Lex Luthor will try to kill him. Lex shows up at that moment and uses the Book of Destiny to send them away.
The Lex Luthor of Earth-167 became President of the United States.
The Clark Kent and Lois Lane of Earth-167 retired from writing to run the Kent farm together. They have two daughters.
The Clark Kent of Earth-167 lost his powers to start a family. This also made him immune to Kryptonite. He is still physically stronger than the Lex Luthor of Earth-38 and has no trouble fighting him when threatened.
Despite encountering several Supermen who were Clark Kent, Lex still cannot believe that the Clark Kent of his world is Superman.
The Bruce Wayne of Earth-99 confesses to killing many people as Batman - so many he lost count.
Kara discovers that the Bruce Wayne of Earth-99 went beyond killing his enemies and also killed Superman, who was sent in to stop him. According to Earth-99's Luke Fox, that was the fight which left Bruce confined to his exoskeleton.
The Clark Kent of Earth-96 is now Editor-In-Chief of The Daily Planet. All the rest of the staff were killed years earlier after someone (presumably The Joker) gassed the building. It is revealed that he and Lois Lane finally did get married sometime after the events of Superman Returns.
Lex attempts to mind-control the Superman of Earth-96 into fighting the Superman of Earth-38. His plan is foiled after Lois gets through to the other Superman, telling him to remember the friends and family that loved him and how they would want their memory to inspire him to great things - not cold-blooded murder.
The Lazarus Pit John Constantine located is on Earth-18 in a seemingly abandoned mine in North Dakota. It turns out the mine is claimed by this world's version of Jonah Hex, who doesn't have the famous scars of Earth-1's Jonah Hex... at least until a fight with White Canary and Mia Smoak results in him getting cut up.
Kate accidentally kills the Batman of Earth-99 while trying to keep him away from a weakened Supergirl. She takes one of the Kryponite discs from his exoskeleton, however, having become fearful of Kara turning upon The Monitor.
Ray Palmer has a gulten allergy. The Superman of Earth-96 does not.
Kate is revealed as the Paragon of Courage. It is further revealed that facing a version of Bruce Wayne that went bad was her test to prove her resolve and moral courage.
The Lazarus Pit restores Oliver Queen's body, but he's now a virtually mindless killing machine. And because of the magical turbulence between worlds, John Constantine can't do the ritual he used on Sara Lance to restore Oliver's soul.
Kara gives Kate a photo she saw in the library of Wayne Manor - it shows the Kate and Beth Kane of that world, apparently happy together at some point after Beth Kane was abducted on Earth-1.
Kara tells Kate that she plans to use the Book of Destiny to restore her Earth, no matter what The Monitor says.
Harbinger is summoned by the Anti-Monitor, who meets her in STAR Labs on Earth-1.
Earth-74: An empty field.
Earth-99: Gotham City: Wayne Manor and the Bat Cave.
Earth-167: Smallville, Kansas.
Earth-96: Metropolis: The Daily Planet Building: Clark Kent's office.
Earth-18: North Dakota: Abandoned Mine with Lazarus Pit
Everything in the past 10 years that took place on Earth-167. (Sorry, Smallville fans!)
The Bottom Line
Like Mary Poppins, practically perfect in every way.