Senate's erratic behavior rattles Ronnie and prompts a telling showdown with Harper; pupil misconduct provokes a new teacher, whose youth belies grit.

A teen's pregnancy sensitizes Guber; a gang slaying deeply affects Kimberly and her prize student; romantic liaisons have differing impacts on Ronnie and Hanson.

Kimberly is stalked by one of her students; Lipschultz celebrates Valentine's Day with Guber's mother.

Sudden fame heartens Ronnie, credited for high exam scores posted at Winslow, yet she's also facing a romantic crisis with Zach; a student-council election tests a shy, awkward teen.