Issa (well, Melissa but... you know...) is an average girl, goes to school, has average grades, likes music, movies & games, a bit nerdy... Oh, and she is a shape shifter. She lives with the Professor who she fondly calls Doctor (she might or might not have asked him for a Sonic Screwdriver) and spends her time doing things that teenage girls do. And investigate the disappearance of her father. Which means she gets into danger, not realizing her father disappeared for a reason: to protect her!
Imagine you are a shape-shifting teenage superhero with awesome powers. You go out every night to fight crime and maybe spy on your crush a little. But what if somebody figures you out? Somebody dangerous. Like, REALLY dangerous!