An alien girl named Cera is stuck on Earth with a teenage girl named Hailey and her little sister Sammy. She has no idea how and why she was sent here in the first place. With only half of her memories intact, she spends her days living with odd humans and fighting off other alien intruders that want her killed. Why do they want to kill her? She doesn't know. How does she fend for herself? She shape shifts into huge, dangerous, and incredible alien creatures. ( haha hows that for a half assed summary. xD)