Michael regrets revealing that Stanley is having an affair, so he spreads a bunch of lies about everyone else to cover his tracks--except that one of the lies that he spread actually turns out to be true.
The Office travels to Niagara Falls to celebrate Jim and Pam's wedding under strict orders not to mention Pam's pregnancy. Michael, Dwight, and Andy all want to hook up with guests at the wedding and Michael and Dwight meet twins.
10 years ago, Michael promised a group of 3rd graders he would pay for their college tuition if they graduated. Now comes time to pay, and he can't do it. At the office, Dwight's "Employee of the Month" idea gets Jim in big trouble.
Michael hates the changes that Dunder Mifflin's new owner is implementing, so he turns to David Wallace for advice. Jim and Pam find the perfect day care center, but Jim's mistake threatens to ruin the interview.
Sabre's CEO wants the Scranton branch to have one manager, and Michael voluntarily steps down and lets Jim become the boss when he finds out that salespeople make more money. However, he soon comes to regret the decision.
Pam goes into labor and Jim is ready to take her to the hospital, but she refuses to go. Meanwhile, inspired by Pam and Jim's baby, Dwight and Angela try to reach a "business agreement" to have a baby of their own.
After the baby is born, Pam has trouble getting the baby to breastfeed. At the office, Michael takes credit for hooking Jim and Pam up, and tries to do the same thing for Kevin and Erin, making Andy jealous.
It's St. Patrick's Day, and the CEO forces the office to work late because she won't leave. In addition, Michael unsuccessfully tries to suck up to his new boss, and Andy and Erin's first date is delayed because Erin is sick.
Oscar gets everybody in the office to go to Happy Hour so that he can hit on a coworker in shipping. Pam tries to set up Michael with a friend at the bar, but Michael's alter ego, "Date Mike," threatens to spoil the entire evening.
Michael is hopeful that a potential client is interested in him, but everyone in the office except Pam thinks he's wasting his time. Meanwhile, Dwight recruits Kelly to apply for the Sabre minority management training program.
Michael becomes convinced that Donna is having an affair and puts Dwight on the case, but Pam soon discovers that the suspicions may be true. Meanwhile, Darryl gets revenge on Andy for an earlier incident.
Michael continues to see Donna even after learning she's married and meeting her husband, Dwight and Angela take their baby contract to an arbitrator, and Jim and Pam struggle to stay awake at the office.
Jo comes to the Scranton branch to find the whistle-blower. However, three different people have confessed to Michael, Michael is protecting them, and the person most people think is the culprit is keeping his mouth shut.