It is the final night of the epic DC cross-over with the Legends finishing off the Dominators with a little help from Team Flash, Team Arrow and Supergirl. And can we see Felicity and Cisco on board the Waverider more often. Those two were so funny as the two were positively giddy at the prospect of increasing their geek cred by time traveling.

In order to defeat the Dominators, the team splits up. Nate, Amaya and Rory go back to 1951 Redmond, Oregon. 1951 is the first time the Dominators made their appearance. Their mission is to kidnap one of the Dominators to determine what is their end game. As mentioned, Felicity and Cisco tag along so they can time travel.

When the Waverider, piloted by Mick, arrives in 1951, Felicity experiences the side effects of time travel and it is hilarious. Nate, Amaya, and Mick bench Cisco and Felicity while they go and get a Dominator. Nate is wearing his new Citizen Steel costume and Mick has some hilarious quips about celebrating the Fourth of July. When Mick, Amaya and Nate knock out one of the Dominators, they in turn get kidnapped by the younger version of Agent Smith, the agent that appeared with the president and butted heads with Lyla on The Flash.

In captivity, Nate uses it as an opportunity to question the Dominator. We learn that the Dominator has arrived on Earth because of the presence of meta-humans. The Dominators wanted to see how much of a threat meta-humans pose to them. Amaya realizes the JSA is the reason why the Dominators have come to Earth.

Back on the Waverider, Felicity is trying to get Cisco to forgive Barry. Cisco cannot forgive someone for changing the timeline that effectively killed his family. The two find out that Amaya, Mick and Nate have been kidnapped and Cisco decides it is up to them to rescue the three. And it is tech support to rescue! As the group is about to leave, they hear the Dominator being tortured. Cisco decides they should rescue him and let him go back to his people via the ship on the Waverider. When the Dominator flies away, we see that Cisco has taken a Dominator communicator that allows them to talk to their new friend.

When the team returns to Central CIty 2016, the communicator goes on and we see the Dominator. He tells the group that they are about to release a weapon to kill all meta-humans but he will spare Cisco, Felicity, Nate, Amaya and Mick for saving him.

Meanwhile, Martin is off at STAR Labs working on a weapon to take down the Dominators. Caitlin calls in reinforcements in the form of Martin’s daughter, Lily, a brilliant scientist like her father. Caitlin notes Martin is being distant to Lily. Martin explains that he created a time aberration by telling his younger self to cherish Clarissa, which resulted in Lily. Martin tells Caitlin that when the Dominators are defeated, he will fix his mistake. Caitlin realizes that Martin wants to erase his daughter from existence. Lily has noticed her father’s distance and in a moment of frustration in her work takes a break. Martin goes to talk to Lily and apologizes for his distance. During their conversation, Lily has a breakthrough and realizes what must be done to get the weapon to work. Martin looks on with pride at his daughter.

Elsewhere, Oliver, Ray, Diggle, Sara and Barry are to meet the new president; Kara is benched from meeting her. The reason why Oliver has benched Kara is that she is his breaking point in his sense of normalcy. Kara is hurt at being excluded.

Team Arrow Legends Flash note that the president is late but when a whole bunch of black SUVs arrive, Agent Smith arrives to say they aren’t going to be meeting her. Smith knows all about the Dominators and how he broker a truce with them in 1951 but when Barry created Flashpoint, it broke the truce. Yes, Smith knows Barry’s identity. Smith says that the Dominators will go away if Barry turn himself in to them.

Meanwhile, Cisco vibes with Nate to the Dominator ship where they meet their old Dominator friend who tells of their plan to release a weapon that will kill all meta humans. Cisco realizes by saving the Dominator back in 1951, he screwed up the timeline.

Barry agrees to turn himself in and is about to do so when Oliver tells he won’t let him do it. Barry says that he can’t stop him but the rest of Team Arrow Legends Flash and Supergirl says they will. When Cisco tells him not to turn himself in because he is a friend, this convinces Barry to fight.

Diggle and Jax alert the team that a Dominator ship has arrived in Central City. Felicity also sees that Dominator ships are popping all over the world. Martin arrives with the weapon and says that it needs to be planted on every Dominator at the same time or else they will realize what is happening.

Soon the Dominators are descending Central City. Team Arrow Legends and Supergirl go and hold off the Dominators while the Flash uses his speed to plant the weapon on each of the Dominators they are facing. When one of the Dominators throw the Green Arrow off a roof, Supergirl flies in to save him. The Flash manages to get the weapon on all of the Dominators in Central City but the aliens have descended across the United States. The Flash and Supergirl uses their super speed to get the weapons on all of the Dominators. Felicity turns on the weapons and the Dominators flee back home and the rest of the Dominators around the world follow suit.

Meanwhile, the Dominators have decided to drop their meta human bomb on Central City. Sara and Cisco are in the Waverider and catch it with a tractor beam but can’t hold it up. Firestorm arrives to transmute it into nothing. At first Jax cannot but Martin tells him he has to for his daughter. Jax is successful and water cascades down.

When all is over, the president is giving a speech about the events and calling. Team Arrow Legends Flash and Supergirl heroes.

When alone, Jax questions Martin about his daughter. Martin explains what happened when he talked to his younger self. Jax realizes he created a time aberration but Martin doesn’t want him to tell the rest of the team as he doesn’t want to lose his daughter.

Celebratory champagne is popped and toasts made. Felicity notes how Kara resembles her when she is in her secret identity while Ray notes how Kara looks like her cousin. This is an obvious nod to Brandon Routh’s past as Superman.

Oliver owes Kara an apology and says his Earth could use a Supergirl while she says her Earth could use an Oliver Queen.

Before she goes back to Earth-38, Cisco gives Kara a gift of a mini portal creator/communicator. This will allow Kara to come and go from her Earth to theirs and also allow her to call Earth-1 should the need arrive. Hence we know how the musical cross-over will work. Mick asks Kara, or Skirt as he likes to call her, to give him a call.

When Agent Smith tries and threaten the team, Kara swoops in and says the president liked her idea of having a DEO and how he has been re-assigned to Antarctica.

Everyone bids Kara adieu as she goes back to her Earth. Sara then goes back to the Waverider to continue on her time traveling adventures.

The episode ends with Barry and Oliver at a bar having drinks but realizing that they saw a life where they were happy and normal but their lives weren’t full.

As for as all of the cross-overs the Arrowverse has done, this was probably the best because it truly spanned the three shows. I felt that Supergirl was better used here than on The Flash but she was better used there versus Arrow.

It is commendable that Grant Gustin, Stephen Amell and Melissa Benoist are all leads in their own show yet had the time to be active participants in these cross-over.

Can’t wait to see how Greg Berlanti tops this next year (that is if all shows come back).