Three high school students are forced to make up a failed chemistry test during after school detention. Over the course of the afternoon, they discover that their eccentric Chemistry teacher, Eugene Yamamoto, has been leading a secret double life as a costumed crime-fighting Power Ranger. When a mutant lobster that Yamamoto left in the hands of the police escapes and arrives at the high school seeking revenge, his students must use the science principles from the Chemistry test that they failed to help him defeat it.
