In this episode of Supergirl, Mon-el is found in a spaceship at the bottom of the bay, and Winn says it’s been there for over a thousand years.
The team sets him up in the DEO’s sick bay to recuperate, and he avoids answering most of their questions. He says he doesn’t know, but there’s only so much you can blame on the effects of hypersleep.
Kara finally kicks everybody out and returns to his side. He says he tried to send a messages to her so many times, telling her he was all right, but before he can continue speaking, she cuts him off and urges him to sleep.
At the first opportunity, Mon-El sneaks into the weapons armory. He knocks out two guards who try to stop him before being rendered senseless by a punch from Kara.
Mon-El tells Winn that he needs his help to get back to the ship. If he doesn’t, people will get hurt, including Kara. Later, Kara discovers Mon-El’s empty cell and tracks the two men down on the ship, where they’re checking the hypersleep pods. A brief altercation between Kara and Mon-El about who’s taking whom back to the DEO results in her mother’s necklace slipping free of his shirt. He hastily tucks it back in, but Kara’s already recognized it. Mon-El tells her he’s not her problem anymore, and she wants to know how he changed so much in seven months. “No, it’s been seven years!” he shouts.
Mon-El explains that he went through a wormhole, and he’s been on Earth in the 31st century ever since. Kara demands to know if he just forgot about her in that time, and if so, why he’s still wearing the necklace. But at that moment, warning sirens blare. Mon-El redirects his powers to the chambers, where the inhabitant starts to struggle in the red liquid, he desperately tries to break the glass, but can’t. All Mon-El will say is that her name’s Imra, she’s from Titan. Later we find out she is his wife.
Samantha conducts one more test of her invincibility by sticking her hand into a pot of boiling water. When nothing happens, she sends Ruby to a friend’s and heads to a house in the country.
She greets the woman at the door as Patricia, and we quickly learn that this was her adoptive mother who kicked her out of the house for getting pregnant as a teenager. Sam asks her questions to find out if she had powers as a child. Patricia says no until Sam explains her newly discovered invulnerability to bullets. Patricia then leads her to the barn, where she stashed an alien pod covered in a tarp.
When Sam approaches the pod, her touch activates it, and it ejects an obelisk. Sam follows the obelisk into the desert, and when her car overheats, she sets out on foot until finally, the ground beneath her rumbles and brown pillars erupt from the Earth.
She enters the cavern, inserts the obelisk, and the woman from her visions appears. She introduces herself and welcomes Sam to the Fortress of Sanctuary, a piece of Sam’s homeworld, Krypton.
Sam’s thrilled to hear that she’s like Supergirl, but the woman corrects her: Sam is so much more than that. She’s the culmination of centuries of work, a being designed to execute justice. “They will call you Worldkiller,” the woman says. “Your justice will burn the world of man.” Then Sam starts to scream and falls to her knees in agony. It passes quickly, and she rises with glowing red eyes.