Belle121211
In this world, if you Forget something, whatever you Forgot is transported to a Court. Things, people, anything. However, you can only Forget things that are yours, and only family members can Forget other family.
When Tessa's parents die, instead of dealing with her grief, she travels to the Leaders of the Court to plead with them to let her Forget her parents. To Forget the grief.
But the Memories and Things have been stolen, and she can't Forget her grief if she doesn't get them back. At first she's hesitant, but they offer her a reward to get it back, since she's human, which means she has more power in the Court than a regular Forgotten would.