“Invasion!” is episode seven of season two of DC’s Legends of Tomorrow.
At the end of the previous episode, “Outlaw Country”, Sara told the Legends that their friends needed them in 2016. This is the final episode of the cross-over.
At the end of the Arrow episode “Invasion!”, Oliver, Thea, Diggle, Ray and Sara had escaped the Dominators’ mothership in a smaller craft, which was followed by the Dominators in a whole bunch of these craft. Fortunately, the Waverider appeared and scooped them up before leaving again. Gideon translated something the aliens said as a statement that they were nearing completion of the weapon. Whatever that was.
Oliver, Nate, Sara, Digg and Ray are back at the S.T.A.R. Labs hanger; Thea has been dropped off back home. Cisco wants details on how they escaped an alien spaceship; Oliver tells him questions can wait. They think that the Dominators are gathering intelligence on meta-human weaknesses and Oliver thinks they should return the favour. By capturing and interrogating a Dominator. Barry points out that they are in short supply, but Nate has worked out where to find one. Using the video of the army fighting them, there are Dominators in Redmond, Oregon. In 1951. Fortunately, they have a timeship.
Cisco and Felicity both want to go. Because that’s who they are but Cisco is still avoiding Barry. Nate agrees and says he will also take Amaya and Mick. The president has also called and wants to meet them. Oliver will take Ray and Sara as backup. Kara volunteers but Oliver speaks to her about that. He wants to minimise Kara’s involvement. Not because she’s an alien but because she’s an unknown quantity. Nothing personal.
On the Waverider, Cisco and Felicity are asking Nate questions about the ship. He has no idea how it works. Back at the lab, Professor Stein is struggling and Caitlin says she has invited someone to help. His daughter, Lily. Who, in The Flash episode, “Invasion!”, Stein met for the very first time. The professor is not used to dealing with small stuff and Ray is busy. Lily has a PhD in nanotechnology though. Which her father didn’t know.
In 1951. Felicity is suffering from time sickness. She and Cisco are told to wait on the Waverider as Nate, Amaya and Mick go looking for Dominators. Nate has the new costume Ray made him. They find the army, which is being ripped to pieces by the Dominators. Rory pauses, wanting to find a weak one. Amaya doesn’t think any of them are weak. On the ship, Felicity talks to Cisco again. About what’s really bothering him. Cisco admits that one reason he left 2016 was to get away from Barry. Who he doesn’t consider his friend. Outside, one Dominator has been left behind, so that’s the one they pick.
In 2016, Lily is reminiscing with her father. He doesn’t remember of course. Yet, anyway. Caitlin takes the professor aside and tells him he’s treating his daughter like she’s a total stranger. Stein states that’s because she is, and it’s not Barry’s fault but the professor’s. He considers Lily to be a time aberration, not a real person. Unlike Barry, Professor Stein ahs the luxury of fixing his mistakes, and he plans to erase Lily from the timeline.
Nate, Amaya and Mick have a Dominator, but they also end up surrounded by a bunch of men in black. Their leader thanks them for catching a specimen, then has the three tranqed. On the Waverider, Cisco says the others will be experimented on. Just like in Stranger Things. He and Felicity have to rescue them. With a crate of guns that Cisco has just found. The others are in a room with the Dominator, and Nate suggests that this is their chance to interrogate one.
Ray, Oliver, Sara and Barry are waiting for the president, who is late. Barry wants to know what happened to Kara, because she’s angry. He didn’t even think that she could get angry. Then a bunch of black SUVs arrive and surround the four of them and men in black get out. Their leader, Smith, who had a go at Lyla previously, tells them the president couldn’t make it. He looks rather similar to the person who captured Nate, Amaya and Mick. Because he is the same man. Barry and the others take out his men and the man explains that the xenomorphs have problems with meta-humans. Because they are a threat. In the past, tech support arrives with weapons and Cisco wants them to let the captured Dominator go. Taking a transponder from the ship they send him back in.
According to Smith, a truce was negotiated with the Dominators 60 years ago. But Barry – and Smith knows who he really is – brought them back because of him messing with the timeline in “Flashpoint”. Which threatened the whole universe. They want Barry. In return, the Dominators will leave in peace. Otherwise they will kill every meta-human. Plus a bunch of normal humans as collateral damage.
Most of the team are not convinced that Barry will be enough. He, of course, is willing to give himself up. Cisco’s trip to the past causes him to realise that messing with time, even with the best of intentions, can have totally unintended consequences. Professor Stein starts to accept that Lily is his daughter. Sara says to Oliver that the two of them started it all. The Dominators still need stopping.