Years ago, the demon Trigon conceived his daughter Raven Taissa Farmiga with the human Arella. When Arella discovered his demonic nature, she fled and was taken in by the mystical inhabitants of Azarath. As a young girl, Raven grew curious about her father and experimented with her powers to learn more about him. Trigon found her and killed Arella along with the people of Azarath. Raven barely managed to seal Trigon inside a magical crystal in what remained of Azarath. Sometime later, Raven joined the Teen Titans, beginning a long, wary path alongside young heroes who would come to rely on her.
In the present, Earth is threatened when Trigon sends a demonic corrupter to the planet, a being that briefly possesses Weather Wizard Rick D. Wasserman after a clash between the Justice League and Legion of Doom. Ignoring Batman's earlier warning, Damian Wayne Stuart Allan helps defeat the entity, but leaves the League with little background on its origins.
To handle the rising danger, Nightwing Sean Maher brings Damian to join the Titans, a team led by Starfire Kari Wahlgren. There Damian meets Jaime Reyes Jake T. Austin, Garfield Logan Brandon Soo-Hoo, and Raven, quickly realizing the group has a different rhythm and chemistry than he’s used to. At first, Damian clashes with the others, convinced he can be a stronger, more decisive leader. Their tensions flare, and during a heated moment with Jaime, Raven uses her healing powers to save him, forging an unexpected bond: Raven sees flashes of Damian’s life, and he perceives Trigon awakening within her.
Meanwhile, Batman Jason O’Mara and Cyborg Shemar Moore investigate the earlier attack. Superman Jerry O’Connell is briefly possessed by one of the entities and lashes out at Atomic Skull, attracting the attention of Diana and Batman. Batman ultimately calms the threat with kryptonite, but the possessed Superman escapes before the kryptonite can fully disable him. Batman tasks Cyborg with tracking the girl who is at the center of these events. Elsewhere, the demonic Superman opens a gate somewhere in the desert, signaling a wider invasion.
Starfire leads the Titans to a carnival to help them grow closer, hoping it will ease the rift between the new teammates. Unbeknownst to them, Raven is summoned by Trigon’s entities, who attack her and force the Titans to intervene. After the assault, Raven shares her backstory with the group, explaining the toll her lineage has taken. Back at their tower, the Justice League attempts to take Raven with them to save their own lives, and the heroes—Flash, Diana, and Cyborg—are briefly possessed. Batman, resilient, knocks himself out with a nerve toxin designed to take down Bane, resisting possession and continuing the effort to protect Raven. The League beats the Titans senseless, but Raven agrees to go with them to avert disaster—only for Jaime to strike Cyborg down and free him from possession.
Raven then travels with the League toward Superman and summons Trigon to Earth. Cyborg wakes and uses Apokoliptian tech to teleport the group to confront the demon in a perilous showdown. Damian stabs Superman with Kryptonite, freeing him from possession, and the now-clear-headed Kryptonian heads to stop the entity from ensnaring Flash and Diana. The League remains on Earth to battle Trigon, while Cyborg and the Titans dive into a journey to Hell to rescue Raven. Robin faces a demon that mirrors his deceased grandfather Ra’s al Ghul Terrence 'TC' Carson in a tense confrontation, eventually overriding the threat.
Raven crafts a spell to re-imprison her father and places it on her forehead, a measure she hopes will keep Trigon contained. Robin convinces a hesitant Raven to stay on Earth with the Titans, choosing to remain with them rather than rejoin the League. In a mid-credits moment, a mysterious costumed girl rides a flying chunk of rock toward the Titans Tower, hinting at new and looming challenges for the team.
