Lamentis-1 is a moon that appears in the Loki series. In 2077, the moon was destroyed during an apocalypse, when its planet crashed into it. After selecting this apocalypse event on Sylvie's TemPad, Loki allies with her to escape the moon and survive.
In the third episode, while Loki is confronting Sylvie at the Time Variance Authority headquarters, Judge Ravonna Renslayer appears, making Loki grab the TemPad that Sylvie is carrying and select one of the apocalypses saved on it to teleport himself and her somewhere else.
After being teleported, Sylvie fights Loki to have her TemPad back. However, when she gets the device and attempts to teleport herself, she sees that it needs to be recharged, before Loki takes it from her hands and conceals it with magic. A meteor suddenly falls between them and Sylvie becomes horrified as she sees that Loki transported them to Lamentis-1 in 2077. She tells him that it is the worst apocalypse saved in her TemPad, in which the moon will crash into the planet, leaving no survivors. They run to escape the falling meteors, although she rejects receiving his help. After finding cover from the meteors and realizing that fighting each other will lead nowhere, Sylvie decides to look for a power source to recharge the TemPad and be able to escape the moon, so the two of them decide to walk to the nearest town.
Arriving at the town, they find it completely abandoned. Sylvie explains that they have around twelve hours until the destruction of the moon and that leaving the town is useless because things will only get worse with more meteors, gravity quakes and the collapse of the society itself. After finding no source with enough energy to charge the TemPad, they come across a solitary hut nearby the town. The old woman inside the hut attempts to send them away at first, but she then reveals to them that everyone from the town left to get a train to the Ark, the vessel that will evacuate them from the moon. Sylvie tells Loki that the Ark should have the energy they need to recharge the TemPad, so they go to the train station at the edge of town. At the train station, there is a long line of people awaiting to board the train. The passengers complain that they have been waiting for hours and the guards are only letting the wealthy enter the train. Loki and Sylvie manage board without a ticket, as Loki disguises himself as a guard and Sylvie enchants one of them to let them in.
They spend sometime inside the train talking about their lives and decide to rest before the arriving at the location of the Ark. However, Loki gets drunk and starts singing to Sylvie along with other Lamentians in the train. Because he is not using his disguise anymore, Sylvie becomes concerned and warns him, but Loki tells her that it is the end of the world and seems like he had too much drink to care about anything. He is then involved in a fight with the guards when they ask for his ticket, resulting in him being thrown off the train. After jumping after him, Sylvie demands her TemPad back, but they realize that the device was broken when Loki fell from the train. Sylvie becomes infuriated and tells him that they are both dead without the TemPad. Loki asks about the Ark, but Sylvie explains that the vessel will never leave because it will also be destroyed by the apocalypse. Loki then suggests that they could hijack the Ark and make it leave the moon before its destruction and Sylvie agrees.
The duo walks to the capital city of Lamentis-1, Shuroo, where a crowd is gathered around the place that the Ark will take off. It is announced that the Ark will be launching in five minutes, surprising Loki as he realizes that the crowd outside will be left to die. Sylvie and Loki attempt surround the crowd to get to the Ark, but meteors start to fall from the sky with the planet coming closer to the moon. Loki and Sylvie protect each other from the meteors and fight together against the guards that try to stop them along the way to the vessel. However, when they get near the Ark, it is destroyed by a giant meteor, leaving them stranded at the apocalypse.
In the fourth episode, after accepting their deaths, the duo has left the place to go sit by a lake to watch the moon be destroyed. During the final moments before the total destruction of the moon, Loki apologizes and Sylvie tells him about her life as a fugitive. She explains how she grew up hiding within apocalypse events to avoid causing branches on the timeline and be undetected by the TVA, but now she is ironically going to die in one. Loki becomes impressed that she survived running away from the TVA since she was a child and almost destroyed the organization by herself, and the par shares an emotional moment, in which Sylvie touches his arm. At this same moment at TVA headquarters, a nexus event is detected on Lamentis-1, causing the timeline to branch. It is an unusual straight-up branch, to the point that the event is detected within an apocalypse where everything is destroyed, so the timeline is unlikely to branch. Agent Mobius questions Hunter B-15 if she has ever seen a branch like this one, but the Hunter replies that she hasn't.
On Lamentis, Loki holds Sylvie's hand and they affectionately gaze at each other while the destruction comes closer to them, but two Time Doors then appear and the TVA arrives to capture them both. After imprisoning the pair in different Time Theaters, Mobius interrogates Loki to find out the cause of the branched timeline on Lamentis-1. Mobius discovers that Loki is in love with Sylvie. He explains that Loki and Sylvie being two Variants of the same being and falling in love is the cause of the nexus event on Lamentis-1 and could potentially broke the reality. Loki later attempts to confess his romantic feelings to Sylvie, referring what happened between them on Lamentis, but he is interrupted by Ravonna who prunes him, sending him to the Void.
In the fifth episode, at the Void, Sylvie tells Loki that Mobius told her about the cause of their nexus event on Lamentis and, although she is clearly not knowing how to behave around Loki, she claims that "Mobius' theory" sounds like another TVA lie. In the final episode of the season, the ruler of the TVA, tells Sylvie and Loki that he knows everything they did during their journey, including their shared look by the lake on Lamentis, commenting that it was a really sentimental and touching moment.