“Fort Rozz” is episode eleven of season three of Supergirl.
Alex is resting with one leg broken by Reign in the previous episode, “Legion of Super-Heroes”, when Kara, Sam and Ruby arrive. Sam is going on a trip, but gets a message saying the sitter has cancelled. Alex offers her services.
At the DEO, J’onn says that Colville said that a Kryptonian priestess from Fort Rozz talked about Reign. Jindah kol Rozz, who the place is named after. She never came out when it was on Earth. Kara threw Fort Rozz into space and they’ve found it orbiting a star. Imra knows the star and says it’s blue and not only will Supergirl not have any powers, the radiation is fatal to men. Kara is willing to go alone; J’onn objects. Imra offers to go with but J’onn wants more.
Supergirl heads to see Livewire, who is working in a diner. No, she isn’t here to fight; she wants Livewire’s help. Supergirl knows Livewire is trying to go straight because Reign is killing criminals. No, she doesn’t want Livewire to help fight Reign, only to help gather some information. Supergirl won’t have her powers and wants Livewire to have her back. Livewire finds this hilarious, but agrees.
Brainy isn’t impressed with the DEO’s tech when Supergirl and Livewire return. Then Psi is brought in as well. J’onn is concerned, but Supergirl thinks it’s a risk worth taking.
Lena is talking to Sam about the trip, but when Lena leaves, Reign takes over.
Supergirl, Psi, Imra and Livewire arrive at Fort Rozz and dock, and Supergirl removes Psi’s blocker. Winn and Brainy are squabbling back on Earth. Supergirl can’t open the door, so Imra does. Inside Fort Rozz, the cells are all open; Brainy confirms there are lifeforms on the loose.
Reign arrives at her fortress and says she’s late because of the human side of her. She’s told that Supergirl and others have gone to Fort Rozz to get more information on Reign. Jindah knows the entire extent of Reign’s mission, and about the other Worldkillers. Get to Jindah before Supergirl does and stop her from talking.
On Fort Rozz, they are attacked by someone who isn’t pleased to see the symbol of the House of El. Livewire and Supergirl take her down, but during the attack Psi used her powers on Imra. Supergirl ends up blocking her powers again; either she can’t trust Psi or Psi lost control of her powers. Either way, she isn’t safe. The prisoner is questioned about Jindah.
Jindah is definitely dangerous, and Fort Rozz is also falling into the star, with their ship attached. Which isn’t good. And Reign is heading there too. Back home, after getting a text message from Maggie, Alex and Ruby talk. And Alex decides to put the fear of the FBI into a girl who was cyberbullying Ruby. Sam, when she isn’t Reign, is becoming really worried about her missing time.