If Memory Serves
Summary
Previously, the Enterprise visited the planet Talos IV where Pike and Spock met the Talosians, beings that can create incredible illusions. Pike fell in love with Vina, an injured Federation crewman in the Talosians' care, but she was unable to leave the planet due to the Talosians' abilities keeping her alive. Pike chose to return to the Enterprise, and Starfleet banned future visits to Talos IV. In the present, Burnham and Spock secretly travel to Talos IV, where the Talosians heal Spock's mind in exchange for Burnham's memories of emotionally scarring Spock which they are interested in observing. Spock reveals that he mind-melded with the Red Angel, a time traveller trying to avert a galactic catastrophe in the future. Stamets attempts to reconnect with Culber, who is going through an identity crisis since his resurrection.
Summary from Wikipedia, CC BY-SA 4.0.
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