My gym teacher is an alien overlord

When Luke's annoying older brother became a superhero instead of him, Luke thought he couldn't get any more disgruntled-- until his friend Lara became a superhero, too. Now Luke's feeling totally left out; even his best friend gets mad at him when Luke's attempts at crime-solving without superpowers go terribly awry. So when Luke discovers an alien plot to overthrow the world, he's got nobody to turn to who'll listen...nobody but his sworn enem...