As Alex slept, Lena filled Eliza in on all of their attempts to rescue Kara. Between M'gann and Lena's tracking device, they had everything they needed to track someone in the Phantom Zone, but no way for the device to home in on the specific person they wanted. Hours passed as the two tossed ideas back and forth. Despite the circumstances that brought them together, Lena really appreciated having Eliza around to hear her ideas. Lillian had always been smart, but she was never nearly as willing to support Lena's ideas. She certainly was never nearly as nurturing as Eliza. Kara had told Lena all about her adoptive mother and how much she loved and cared for Kara as her own, but now that Lena knows the exact details of Kara's origin and adoption, her admiration of Eliza's ability to make Kara feel safe after such tragedy increased exponentially. If she were honest, Lena was a little jealous that her adoptive mother hadn't been like Eliza, but she was here with her now, and that was more than enough for Lena to get the support she needed to keep fighting to bring Kara home. Just as she had done with Alex, Eliza eventually convinced Lena to get some sleep, and Lena went to join Alex and Kelly, who had snuggled up to Alex a few hours ago, and really slept for the first time in days.
Now alone, Eliza finally had a minute to take in everything she had learned. She allowed herself a few moments to cry for her daughter who was trapped, alone and afraid, in the worst place Eliza had ever heard about. She thought about how Kara brought light to every room, how she loved so fiercely even in the face of all the bad she had seen, and it made her so angry to think that someone as gentle as Kara could suffer such a fate. Kara didn't deserve this, and despite Eliza's forgiving nature, she vowed to tear Lex Luthor apart if she ever had the chance. Eliza pulled herself together and moved about The Tower, cleaning up and gathering her thoughts about the next direction to take their research.
When Alex, Kelly, and Lena returned to the atrium the next morning, Eliza greeted them with breakfast and a smile. She glanced toward the stairs on the other side of the room, where Brainy slept with his head against the wall, Nia curled up with her head in his lap. "They returned in the middle of the night," she said. "They were discovered by other aliens in the past and had to return to the present before altering the future forever. I'm sorry, but they couldn't get Kara's DNA." Alex visibly shrank into herself, as if physically trying to hold herself together in the face of yet another failure. Eliza quickly made her way to Alex, wrapped her in a hug, and said "don't panic, Alex. I think I might have something," Eliza said. "But it's going to take all of us."
During her late night brainstorming, Eliza had used The Tower's computers to pull up all of her past research on Kryptonian biology. She and Jeremiah had become leading scientists in the field of alien biology when Clark arrived on Earth, and actually living with Kara had only made her more of an expert, especially with Kryptonians. Eliza had kept careful track of Kara's radiation signature, recording it weekly when Kara was growing up, making sure to note the steady changes as Kara got older. Eliza explained to the group that she might have a way to recreate Kara's radiation signature.
"We already tried that, mom. Her radiation signature has changed in the Phantom Zone. The trackers won't pick it up" Alex said, grateful for the help, but frustrated that Eliza didn't seem to have anything new. "Lena told me," Eliza said. "That's what gave me the idea. I'm not talking about tracking her radiation signature, I'm talking about using it to replicate her life force. You and Lena saw promising results using Kara's energy from the memory crystals instead of an actual piece of her DNA. When Kara burns sunlight, she doesn't just create a signature that can be tracked on Earth. She radiates physical energy that can be harnessed. It's unique to her. It won't even match Clark's, since he burns energy at a different rate after all of his years on Earth. It's not just the radiation she gives off. It's what gives her the energy she needs to maintain her powers. It's as close to her physical life force as anything I can imagine." Eliza began speaking more animatedly as she saw a spark of recognition in Alex's eyes. "I expect that you couldn't find her heat signature because the Phantom Zone doesn't have a yellow sun, and Kara wouldn't be giving off as much heat. But, if we do this in time, her body should still have enough stored solar energy for the recreated life source to match hers." Eliza finished talking as Alex nodded her understanding.
"Oh my god." Alex said. "We can use her radiation signature to reproduce her energy. If we can find a way to contain it in the crystal … Mom, this might actually work!" Eliza smiled and surveyed the room. Kelly had wrapped Lena in a hug as if to help her contain her emotions. "It won't be easy," Eliza said. "Alex, you and I will head to the lab to start working on reproducing Kara's energy signature. Lena, I need you to go to the Fortress to get more memory crystals and start trying to figure out how to use them to contain the energy."
"But -" Lena started. "Oh, come on Lena," Alex said, anticipating Lena's hesitation. "Of course we trust you to go to the Fortress alone. Take Brainy if you want backup, but you don't have to worry about us. How many more times do I have to tell you that we trust you?" "At least six," Lena quipped, but her smile was sincere. Alex smirked and gave Lena a playful eyeroll. "I'll let Brainy get reacquainted to the present for a few more hours and pick his brain when I get back. Thanks, Alex," Lena said, opening her portal watch and disappearing into the Fortress.
"What can I do?" asked Kelly, turning her attention from the portal back to Eliza. Eliza handed Kelly a flash drive. "This is everything I learned about the Phantom Zone from Clark and Kara after they came to Earth along with everything Alex gathered from Alura's hologram. This will give you the best look we can get at what Kara might be going through. Could you study it? It might give us insight on how to get Kara out, but I think, even moreso, that she'll need someone to talk to when she gets back. Someone who knows how to help people who have experienced trauma at this level." Kelly nodded and placed a hand on Eliza's shoulder. "I'm on it."
Alex called J'onn and M'gann to update them on the new plan and tell them to be ready to roll at a moment's notice and then followed her mom to the lab. Everyone dove into their tasks, focusing all of their energy on what felt like the most promising lead they had gotten since Kara was sent to the Phantom Zone. The day turned into night, night turned into morning, and the days started to creep by. Alex and Eliza managed to reproduce Kara's energy signature, but turning it into a form that could be housed by the memory crystal was another matter entirely. Lena and Brainy worked tirelessly, but what sounded like a straightforward enough plan turned into almost two weeks of work. Finally, the tired, frustrated, yet still hopeful SuperFriends were able to contain the energy in a crystal and load it into Lena's tracking device. "It's been almost a month since she's been gone. Do you think Kara's solar energy is still strong enough to be tracked?" Alex asked her mom, voicing the concern that nobody dared mention until now. "I know it is," said Eliza. "Kara's not one to disappoint."
With that, Alex, J'onn, M'gann, Nia, and Brainy suited up while Lena turned on the Phantom Zone hologram and fired up the tracking device. After what seemed like forever, the tracking device started beeping in tandem with a flicker of light on the map. "There she is," Lena, whispered, not wanting to say it too loudly in case she was wrong.
Alex nodded, steeling herself for the task ahead. Eliza headed to the med bay in anticipation of Kara's needs when she returned. Lena and Kelly stood side by side, preparing to monitor the portal and comms to ensure mission success. "Let's go get our girl," Alex said, leading her team into the Phantom Zone, prepared to get her sister back no matter what.