Prologue:
Deep in the vastness of inter-dimensional space, Trigon the Terrible has an idea. With a wicked grin set in his profane features, he sets about the work required to see the still-forming plan to fruition. As arcane energy swirls about him, his thoughts leap to his gem, his daughter, his Raven. "Yes, this will be a most glorious plot. I only need... ah, of course. The answer is right there."
...
Elsewhere, on Earth, nestled in a bay on the outskirts of Jump City, sits a tower that is now as much a museum as a relic, as the Teen Titans have grown up past the 'Teen' part of their team moniker, and as such, left the old headquarters behind.
Robin, now Nightwing, has relocated to Bludhaven, and sometimes frequents Gotham to pursue either a romance with Barbara Gordon/Oracle or assisting his mentor The Batman in the protection of the dark city, and he couldn't be happier. Could he?
Cyborg, now a full member of the Justice League, assists the other League members as needed and spends much of the rest of his time on the Space Station, avoiding contact with average people in an effort to avoid the odd stares his half robotic body wins him, and he couldn't be happier. Could he?
Kori'Ander, Princess of Tamaran, has returned to her native planet to rule it as their Queen, where she uses the lessons learned on earth to initiate a renaissance of sorts on Tamaranean warrior culture, and she couldn't be happier. Could she?
Raven has taken an apprenticeship under Dr. Fate, honing her arcane talents and deepening her mystical understanding, and she couldn't be happier. Could she?
Beast Boy, now calling himself 'Changeling' -when such names are useful- wanders the wild places of the world, living as much as a beast as he does a man, and he couldn't be happier. Could he?
Well, obviously not. One universal truth; things always change.