On the Nazi-controlled world of Earth-X, a team of scientists are working when Dark Arrow arrives and shoots down the scientists and their guards. An armored Guardian steps out of the shadows and attacks Dark Arrow, and Dark Arrow finally stabs him with a knife. He kicks the helmet off of Guardian, revealing James Olsen. Dying, James says that there are more like him, and they will free the world. Unimpressed, Dark Arrow tells Guardian that the American flag he's wearing doesn't exist anymore and shoots James dead. Dark Arrow then finds the portal device that the scientists were working on and says that with it, their reign will last for eternity.
On Central City, Flash is fighting King Shark. Iris tells him that they have a problem with their wedding, and Flash says that it isn't the best time. As Flash knocks out King Shark, Iris says that everyone hasn't RSVP'd.
In Star City, Arrow is fighting ninjas when Felicity contacts him to say that they're having trouble. She tells him that Barry and iris need to know if they're going to their wedding. He agrees and felicity sends an SVP.
In England 1183, an old man asks for alms from riders heading to Nottingham. The Legends attack them and White Canary wonders if they RSVP'd for Barry and Iris's wedding. Waverider arrives overhead and they board to head for the wedding.
In National City, a businessman is on the phone and heads to his car. Supergirl and a Dominator crash into it and she tells the DEO what she's dealing with. She knocks it unconscious and flies off. Mon-El shows up at the DEO and asks if Supergirl is okay.
That night at Kara's apartment, Alex tells Kara that Mon-el asked about her. She points out that Mon-El is married and Alex finds the invitation to Barry and Iris' wedding. Kara says that she's in no mood for a wedding, and points out that Mon-El was also invited. However, she refuses to sit around and wallow in depression, opens a dimensional portal with Cisco's breaching device, and tells Alex that they're going to the wedding.
Waverider lands in Central City and cloaks, and Supergirl arrives via the portal. The woman go to a nail salon for treatments and drinks, Iris asks if Felicity and Oliver will be getting married next, and Felicity says that they will as soon as Oliver deals with all of his issues.
Barry and Oliver are getting fitted for tuxes, and Barry worries about his vows. Oliver assures him that he'll find the words once he's up there, and Barry asks Oliver if he's ever thought of making it official with Felicity. His friend says that it isn't the right time, and Barry tells her to put a ring on her because people like them will always be getting into trouble.
At S.T.A.R. Labs, Cisco helps Jax make a decelerating serum to neutralize the Firestorm matrix. As Cisco and H.R. start arguing. Martin interrupts and they explain that they're going to trick the particles to think that they're still merged. One of them takes it and their back to their old selves. As Martin says that he'll take it after the ceremony, a not-so-thrilled Jax says that it's everything that they wanted.
On Earth-X, a scientist tells Dark Arrow that the rebels' equipment is excellent but he needs time to test it. Overgirl flies in and tells the scientist that he has one day, and Dark Arrow agrees.
At S.T.A.R. Labs, Caitlin tells Martin that it's just about time for the rehearsal dinner. They talk about Ronnie and Caitlin says that Ronnie would be happy for them. She asks what Martin will do when he's no longer Firestorm, and Martin hopes that he'll be a husband, father, and grandfather. Caitlin goes on ahead and Martin goes back to his microscope.
At Jitters, the group meets for their rehearsal dinner and Mick hits the open bar and free buffet. Alex is drinking heavily, and Sara joins her and figures that Alex is trying to make something go away. When Sara wonders what happened, Alex says that she broke up with her fiancée because they wanted different things. Sara offers a toast to making things go away. Barry finds Kara and points out that she doesn't have Mon-El with her. Kara explains that he's married to someone else, and she forgot that her lie should only be about Supergirl. Barry says that she has to accept love into her life, and Kara insists that she's different because she's alone. He then asks her to sing for their wedding.
Martin comes in late and greets his wife and daughter. He calls Jax aside and shows him the serum that he's been working on, and explains that it will give Jax superpowers taken from a moss spider. It will let him stick to things, and Martin figures that Jax can still be a Legend. Jax isn't impressed, but before he can explain, Joe offers a toast. He talks about how the couple is special, and talks about how he's been happy to be dad to them. Joe has seen them face everything with love, and he calls Danielle up and thanks his foster son and daughter for showing him that love is the most important thing that they have.
In the shadows, Alex and Sara are kissing.
Oliver suggests to Felicity that they should consider getting married. Felicity is shocked and says that she loves their life and what they have, and says that they don't need a piece of paper to show that they love each other. She doesn't want to make it legal, and loudly says that she doesn't want to marry hm. Everyone hears her and stress, and Felicity walks off.
Barry sits next to a sleeping Iris and then speeds off.
Oliver and Felicity sit separately, staring at the ceiling.
Alex wakes up in bed next to Sara. Surprised, she slips out of bed and falls on the floor.
At the Stein house, Martin looks at a sleeping Jax. Mick is wearing his wife's dress and says that he found the milk.
Iris wakes up and finds coffee, a Danish, and a note from Barry saying that it's bad luck for the groom to see the bride before the wedding.
Later at the church, Alex walks up and Kara asks where she's been. Alex claims that she was out jogging, and says that she didn't do anything she wouldn't have done on their earth. Sara walks up and reminds Alex what her name is, and makes small talk. When Sara mentions that she heard Alex fall out of bed, Alex tries to pass over it and Alex wonders what she did while Kara starts laughing. She tells Alex that she's a single healthy lady and had a good time at a wedding.
Inside, Mick sits on the bride's side next to Captain Singh. Singh wonders if he knows Mick, just as Cecile comes over and greets Singh. A caterer offers Barry sparkling water, and says that she's excited to be there. She tells Barry that it's going to be one for the ages, and Barry wonders if they've met. The caterer rather unconvincingly says that they haven't and walks away.
Kara goes up to sing, and Joe brings Iris in. Everyone takes their seats and the minister begins the service. After saying that they must be in love because of all of the friends that came for the service, the minister asks if anyone objects. A beam disintegrates him, and Dark Arrow, Overgirl, and a group of Nazi soldiers come in holding guns.
They open fire, and Barry superspeeds to catch the bullets. Martin and Jax become Firestorm, As Barry superspeeds the non-superpowered guests out of the church, Caitlin becomes Killer Frost and Mick opens fire with his heat gun. Sara and Alex take on the soldiers in hand-to-hand, and Barry catches the bullets and throws them back into the soldiers' rifles.
Kara and Overgirl clash in mid-air, and Kara realizes that Overgirl is just as strong as she is.
Dark Arrow opens fire, and Oliver prepares to fire back.
Kara knocks Overgirl into the air and speeds up after her.
A masked swordsman, Prometheus, confronts Alex and Sara.
Oliver deflects the arrows that Dark Arrow is shooting at the guests.
Sara grabs a censor and attacks Prometheus, and Alex joins in.
Cisco and Killer Frost attack the soldiers.
Supergirl and Overgirl fire heat beams at each other as Joe looks on from below.
Wally catches Dark Arrow's arrow, and Cisco opens a breach so that Oliver can attack Dark Arrow. Dark Arrow deflects the arrow and the two fight hand-to-hand.
Alex knocks Prometheus out.
Oliver and Dark Arrow fight.
Overgirl knocks Supergirl back into the church, stunning a nearby Cisco, and flies in after her. Kara slaps her hands together, generating a sonic boom that stuns her opponents an staggers everyone in the church. She then punches her counterpart. Dark Arrow runs to his comrade's side and helps her up, and tells everyone to fall back. They retreat through a dimensional portal and disappear.
That night, the heroes regroup at S.T.A.R. Labs with the captive Prometheus. Barry apologizes to Iris and she assures him that she's fine. He promises that he's going to marry her. Meanwhile, Martin tries to wake Cisco up, and Caitlin confirms that he is kay but has a concussion. She then explains to Martin that she becomes Killer Frost when she's angry or scared.
Alex and Sara lock Prometheus up in the pipeline.
Barry asks Wally to keep their families safe, and Wally reluctantly agrees.
Mick confirms that he wiped the minds of everyone at the wedding. Kara has scanned the city and didn't find the Nazis that attacked them. They wonder how Dark Arrow and Overgirl matched them, and Oliver says that they should make Prometheus talk.
On the rooftops, Dark Arrow approaches Overgirl and points out that Kara was stronger than they anticipated. Overgirl says that the next time Kara won't be so lucky, and a speedster joins them. He removes his mask, revealing that he's Harrison, and complains that they attacked before they were ready. Dark Arrow removes his mask, revealing Oliver's face, and says that they had an opportunity. Harrison complains that they lost Prometheus, and Overgirl removes her mask to show Kara's face and says that they will have another chance to achieve victory and then they will kill all of them.
Written by Gadfly on Dec 3, 2017