A.P. Bio

Jack decides to use his students to enact revenge on his rival; Principal Durbin struggles to control Jack.

When Jack leaves his class unattended, a student gets injured, landing Jack in "teacher jail"; a teacher's union representative sets her sights on Durbin; the students are excited about a substitute teacher until they find out it's Helen.

Jack puts his students on a new revenge mission; Helen, Principal Durbin's secretary, relentlessly tries to get Jack to make something for the annual bake sale.

When Jack gets into a petty dispute with the student council president, the situation escalates much too far; Stef sells makeup at school as a side business.

Jack reluctantly agrees to go out on the town with Mary, Stef and Michelle; his superiority complex proves difficult for the women to overcome; principal Durbin feels threatened when Helen fills in for him on the school's morning announcements.

When Jack is attracted to a student's mother at a parent-teacher conference, he feigns interest in her son; a group of parents complain to principal Durbin when they notice a piece of controversial student art from Mary's class.

Jack receives an offer from Miles' publisher to write a book of feel-good philosophy, which could be his ticket out of Toledo; Durbin accidentally sets off an emotional firestorm when he reveals who Mary chose as her emergency contact.

Jack finds out his ex-girlfriend needs a venue for a charity fundraiser and suggests a student's house; the kids are inspired by Jack to party for the first time.

Jack is incensed when his dead mom's former lover shows up and suggests they celebrate her birthday; Jack taps his students to help him retaliate, but they are busy caring for robot babies; Stef's kindness toward the janitor sends the wrong signals.

Jack takes in Durbin after giving him marriage advice that backfires and gets him kicked out of the house; the kids try to help Jack get revenge against Miles.

One of Jack's students anonymously reports him for canceling their much-anticipated fetal pig dissection; Jack sets out to find the snitch; Durbin's chances at Principal of the Year are in jeopardy when the superintendent visits.

Jack successfully convinces Miles that Devin is his illegitimate son; Durbin, Mary, Stef and Michelle clash on the Sadie Hawkins dance theme.

Jack takes interest in a revenge mission on behalf of the kids; Mary, Stef and Michelle believe they've discovered an otherworldly presence.