The one I remember was the storyline where there was a virus released by Ra’s Al Ghul in Gotham where Tim Drake had caught it but was cured. However those who were previously infected were now dying from it again. When Batman discovered this, there was a final panel showing Tim Drake looking at Batman to ask what was wrong and the glass case with Jason Todd’s Robin costume was right behind him as foreshadowing.
Contagion and Legacy were the storylines.