Mike is inspired by their honeymoon trip to Paris to change his life and travel the world, while Molly worries how their family and friends fared at home without them.
When Vince throws out his back, Joyce conveniently disappears, leaving Mike and Molly to care for him. Meanwhile, the newlyweds struggle to write personalized thank-you notes for their wedding gifts.
Mike and Molly decide the time is right for them to start trying for a baby. Meanwhile, Carl gets upset when he learns that Molly is still spending time with Christina after their breakup.
With the house feeling too cramped and crowded, Molly plans a family yard sale. Meanwhile, Mike and the guys take Carl on a fishing trip to help him forget his breakup with Christina.
When Mike gets sick for Thanksgiving, Molly is secretly thrilled because she won't have to cook... until Vince invites his brother, Frankie (guest star JON POLITO), to town for a homemade Thanksgiving meal.
Molly encourages Mike to pursue a detective position on the force, but the stress of taking the qualification exam starts to take a big toll on their relationship.
In an effort to boost their chances of getting pregnant, Molly encourages Mike to join her in giving up caffeine and eating healthier, causing them both to have major withdrawals.
Mike prepares to spoil Molly for her birthday, but his plans go awry after he eats psychadelic gelato made by Victoria's friend, Tom (guest star DAVE "GRUBER" ALLEN), and goes on an unexpected trip.
Mike begins transforming the basement into a living area for he and Molly to live in, but the construction work is more than he - or his eyebrows - can handle! Meanwhile, Carl invites Samuel to move in with him.
Mike and Molly encourage Harry to take Victoria on a date for Valentine's Day, and everyone is shocked when she accepts. Meanwhile, Carl convinces Samuel that they will be able to meet women at the laundromat during the holiday.
Mike studies male fertility and visits a clinic to ensure that his "swimmers" are up to the task of starting a family with Molly. Meanwhile, Vince gets a new job selling vacuum cleaners door-to-door.
Carl and Samuel host a St. Patrick's Day party in hopes of attracting some lucky ladies. Meanwhile, Molly reveals juicy secrets from her previous St. Patrick's Day excursions to Mike.
Molly joins her sister on a Spring Break road trip to party with Victoria's friends from junior college, while Mike pulls some strings with his boss for some overtime assignments.
Even though Mike's birthday wish is to have his wife and mother get along, Molly and Peggy can't seem to play nice as they try to plan his birthday party together. Meanwhile, Carl and Samuel compete for the same woman.
After learning that Joyce gave up her artistic talents when she became a mother, Molly decides that she and Mike need to pursue new hobbies before becoming parents. Consequently, Molly encourages Mike to take up roller-skating with her!
Mike goes on a junk food binge to cope with missing Molly, while she's out of town for a teacher's conference. Meanwhile, Carl contemplates leaving Chicago after learning heartbreaking news from James (guest star LAMONICA GARRETT).
Molly is so focused on directing a school recital that she doesn't realize a fellow teacher is hitting on her. Meanwhile, Vince convinces Mike to join him in an unusual money-making scheme. TIM CONWAY and JIM BEAVER guest star.
In the third season finale, Mike and Carl get stuck working at the Renaissance Faire after their boss, Captain Murphy, gets dumped by Mike's mother. Later, as a tornado descends on Chicago, Mike and Molly each confess important news to each other.
