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

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

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

When Jack casually gives Durbin some marriage advice, it backfires, gets Durbin kicked out of the house, and Jack takes him in. The A.P. Bio kids tell Jack if they can get Miles' DNA, they'll learn a little biology while pulling off the ultimate revenge.

Jack is incensed when his dead mom's former lover shows up and suggests they commemorate her birthday. Jack taps his students to help him retaliate, but the students' hands are already full - of crying robot babies. Stef's kindness toward Dale the janitor sends the wrong signals.

Jack finds out his ex-girlfriend Meredith needs a venue for a charity fundraiser and has the perfect place: his student Victor's house. Victor and the other kids are inspired by Jack to party for the first time.

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

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

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

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

Jack gets into a petty dispute with Marcus, the President of Student Council. Marcus surprisingly refuses to back down and the situation escalates much too far. Stef sells makeup at school as a side business.

When Jack leaves his class unattended, a student injury sets off an official investigation and lands Jack in "teacher jail." An aggressive teacher's union rep sets her sights on Principal Durbin. The students' excitement for a substitute teacher are dashed when they find out it's Helen.

Jack Griffin is a Harvard philosophy scholar who loses out on his dream job and goes to work as a high school Advanced Placement biology teacher in his hometown of Toledo, Ohio. He quickly makes it clear he will not be teaching any biology, however, and, realizing he has a room full of overachieving honor roll students at his disposal, decides instead to use the kids to enact revenge on his rival and take the job that is rightfully his. Eager to prove that he is still king of the castle, Principal Durbin struggles to control the force of nature that is Jack Griffin.