This week, the The CW Network four-way crossover wraps with "Legends of Tomorrow" Season 2 episode 7 with a title, "Invasion." Apparently, this episode is successful.
According Comic Book, "Legends of Tomorrow: Invasion" raked in 3.33 million and scored 1.1. Episode 7 first revealed that Nate Heywood has dropped Thea off at Star City, and after Oliver revealed what they have learned from being captured by the Dominators, the team decided to capture a Dominator from the past for questioning.
Using the Wave Rider, Nate, Mick, Amaya, Cisco and Felicity traveled back to 1951 Redmond, Oregon to abduct a Dominator for questioning. Leaving Cisco and Felicity aboard the Wave Rider, much to their protest, Mick, Amaya and Nate set off to where the battle between the U.S. military and the Dominators are battling it out. They were able to capture a Dominator, only to be captured themselves by what seems to be government operatives.
In the present, during a botched meeting the new President of the United States, Flash, Green Arrow, White Canary and the Atom discovered from the older version of the agent that captured the Wave Rider crew in the past, that the reason why the Dominators are invading Earth is because Barry messed with the timeline. Also, the Dominators would like them to surrender Barry to them as a sign of good faith and for them to end their invasion.
Back in the past, the Legends were rescued by Cisco and Felicity, and during their escape, they freed the captive Dominator with hopes that this would change the outcome of the future for the better. This however backfired as this actually changed the course of the future, where the captured Dominator's horrible experience in the past gave them even more conviction to finish their mission in the future.
While all of this is happening, with the help of his new found daughter, Martin Stein was able to develop a weapon that can cause the Dominators extreme pain, IGN mentioned. Later on, Barry decided to give in to the Dominators' ultimatum and give himself up, but was talked out of it by the rest of his team.
The team ended fighting the Dominators on a rooftop. Amidst the Heroes vs. Aliens melee, Barry was able to place the weaponized devices on the Dominators, and with the help of Supergirl, was also to place the devices on the Dominators across the country.