Ace is only five when she is a witness to her father's, (The Joker) death. However, his death was not an accident. Several years later- her mother, (Harley Quinn) is in deep sorrow and not coming out of it. Her father's empire is now hers- until she finds evidence that he may be alive. Ace fights to get the evidence she needs to prove to not only her mother, but her twin siblings and all of Gotham that The Clown Prince Of Crime didn't indeed die that night. (Ayerverse)