Titans, Vol. 1 #23A

Who is Troia?, A Night to Remember
No one remembers Donna Troy, although the fact that she knows Nightwing's first name at least gets him to listen. Even her former boyfriend Kyle Rayner does not remember her. Desperate, she flies around the city looking for answers. And doing that. she's able to intervene when Shockwave tries to kill mayoral candidate James Hall (Arthur Hall). She and a mysterious Epsilon stop the villain. Better yet, Epsilon knows who she is... until the battle ends, when he apparently does not! (This is a ruse on his part). Even Donna's adoptive mother does not know who she is! But someone does - Dark Angel, who has somehow separated Donna from her friends' memories! Fortunately, visitors from another world, the Kingdom Titans (Earth-22) do remember Donna, and will stand with her. And in Titans tower, Dick tells Roy why be believes Chanda sold Cheshire to Deathstroke. Roy discovers Chanda packing, certain he will fire her. He wasn't planning to - but she quits anyway. She knows Quraci terrorists know of her connection to the Titans and would use that, and therefore that her presence is to dangerous to Lian.
Release Date: 2001