Superheltefilmen 'X-Men: Dark Phoenix' bliver den 13. kapitel i filmserien sat i det store X-Men-univers, der startede med X-Men fra 2000. Filmen udspiller sig i 1992, altså ni år efter begivenhederne i forgængeren X-Men: Apocalypse. Den vil fokuserer på Jean Greys forvandling til den mægtige Phoenix og er baseret på tegneserien 'The Dark Phoenix Saga' af John Byrne og Chris Claremont. Den telepatiske mutant påvirkes af et voldsomt soludbrud, som fremkalder hendes mørke side kendt som the Phoenix, der har uanede kræfter.
Sophie Turner, best known for her performance of Sansa Stark in the “Game of Thrones” film series, is Jean Grey / Dark Phoenix here. The young woman is gifted with unique but viperous powers that take hold of her in a cosmic accident. Little by little, these powers start corrupting Jean and ruin her authentic personality, making her do things that hurt people. While she can no longer resist their pressure, Jean is turned into the Dark Phoenix. At the same time, Professor X is torn by a terrible dilemma - to sacrifice one of his own team in the name of the entire group, or to try and save Jean. When the existence of humanity is jeopardised, the powerful X-Men are quickly united into the force that no one could defeat.