The End (2) (S04E12)

Robin, Starfire, Cyborg, and Beast Boy wake up to a horrifying reality. Trigon has returned and annihilated the world. With every structure in ruins and all living beings turned to stone, the Titans find themselves as the last survivors thanks to a final gift from Raven. Determined to rescue her, they believe she might hold the key to defeating Trigon. However, to succeed in their quest, they must reluctantly seek assistance from their former foe, Slade.