Solitude (Supergirl)

"Solitude" is the fifteenth episode in the first season of the CBS television series Supergirl, which aired on February 29, 2016. The episode's teleplay was written by Anna Musky-Goldwyn and James DeWille, from a story by Rachek Shukert, and directed by Dermott Downs. The episode is named for the Superman's Fortress of Solitude in comic books and related television and film series.

Plot
In the Phantom Zone, Kara notices a computer console light up with the three dots of Brainiac, before her pod begins towing the prison ship Fort Rozz. In the present, Kara refuses to return to the DEO because of Hank. At CatCo, everyone is in a conference call, when Siobhan presents a package to Cat, who wants it open for all to see. James finds a letter and thumb drive inside; unimpressed, Cat tells Siobhan to microwave the drive. Alex and Hank spar and debate over whether Kara should know the truth. At CatCo, all electronic devices star to go haywire. A hacker broadcasts through the monitors, warning she will bring chaos to National City; immediately, the traffic signals are disrupted. Supergirl arrives to help, and Cat tells James to get all personnel on the cyber attack.

Kara and James watch Winn attempt cracking the code to no avail. The hacker teleports through the computer into the room, as a blue woman with the symbols of Brainiac. She and Kara are fighting, when Hank and Alex join them. They attempt convincing Kara to return to the DEO. Moments later, the cyber-woman, Indigo, teleports away. Indigo tells Non that Astra's notion of living alongside humans cannot work, and vows that she and the Kryptonians will be the only ones left on Earth.

Alex stops by CatCo, wanting Winn's help with disabling the malware. James takes a frustrated Kara to the Fortress of Solitude, where the answers lie in a computer named Kelex. Kelex reveals Indigo was Fort Rozz's deadliest prisoner. James thinks Hank should know, but Kara wants to go it alone. Lucy is upset at James, and storms off to tell her father about Indigo hacking military cyber-systems. Indigo disables the military site's codes and activates missiles. Kara fights Indigo, but she escapes. With Hank's help, Kara goes after the missiles. Indigo sends more missiles, but notices Winn has begun sending a virus—she teleports her arm through a screen and begins choking him. Indigo reveals that she was the one who brought the pod and Fort Rozz to Earth, before she disintegrates from the virus.

Kara gives James her blessing to tell Lucy the truth, only to have Lucy break up with him, believing that Kara loves James back. Kara is ready to work with Hank again; Alex comes clean to Kara, admitting to killing Astra. She let him take the blame because she did not want to lose Kara. Kara and Alex hug, with Kara reaching out to hold Hank's hand. Meanwhile, Non places a spinning ball on a computer—a new version of Indigo materializes in pieces, with Non saying that they will do things his way.

Ratings
The episode attracted 557,000 viewers for its British premiere, making it the 10th most watched programme on Sky One for the week.

Critical response
Cliff Wheatley of IGN gave the episode a 7.2/10: “Solitude” was a great episode for Supergirl herself with a whole lot of fun teases and easter eggs for comic book fans. The ending with Supergirl forgiving Alex was one of the most genuine and pleasing moments of the show, but it was also an episode laced with silly techno-babble and a love triangle dynamic that was hard to get behind."

Stacy Glanzman of TV Fanatic gave the episode a 3.8 out of 5 stars.