Doll Bones by Holly Black
/Zach, Poppy, and Alice have been friends forever, and they’ve been playing one continuous ever-changing game just as long, an imaginative game with pirates, thieves, mermaids, and the Great Queen who reigns over them all, inspired by Poppy’s mother’s bone china doll. But when Zach’s father finds out about the game, he forces him to quit. When it seems like their friendship might be over, Poppy declares that she’s been having dreams about the Queen and the ghost of a girl who will not rest until the bone-china doll is buried in her empty grave.