Rusty Barker is a gruff, no-nonsense guy, but someone who cares more about people than he lets on. The story takes place during the spring of 2005, a few months before he retires. The assistant principal asks him to chaperone the prom when another chaperone drops out. Rusty had never chaperoned anything before.
The first "painful surprise" is how loud the music is, which he's not prepared for. Later, Rusty hurts his neck -- not seriously -- when he gets roped into dancing.
It's basically a slice-of-life kind of story, with the funny conversations Rusty has with students and with other faculty members driving the action.