Annie is livid when her father brings along his girlfriend on a weeklong visit; Mary and Matt pursue new romantic interests; Lucy wants to find out if blondes really have more fun.

Mary undergoes knee surgery, while Matt learns that Michael Towner was the hit-and-run driver; Wilson reveals the truth about Billy to Eric.

Eric and Annie's parents arrive right in the middle of the crisis involving Mary and Matt; and Happy's original owner comes to take him back.

Annie's father, Charles is getting married to his girlfriend Ginger. The wedding reception is supposed to be at the Camden's house and Annie is the one in charge of preparing the menu. Annie isn't enthusiastic about the wedding and the reception. On her way to the grocery store, she meets a homeless veteran and invites him home. He is the one ending up preparing the menu since he was a chef for forty years. Also, Matt and Mary are taking a little road trip, which ends up being very long when they get a flat tire. Simon is spending the day with his new girlfriend Deena. Lucy is spending the day with Jordan, the guy she can now call her boyfriend. Lastly, Ruthie is feeling lonely, so she pretends her imaginary friend Huey is back the whole day.

When Ginger pays the Camden family a visit, she informs Eric and Annie that her father is in the early stages of Alzheimer's Disease. At first, Annie can't believe it, but after observing him in the backyard and not paying attention to a fire in the barbecue, Annie realizes the truth. Meanwhile, Mary and Eric can't see eye-to-eye on her relationship with Robbie, but they soon agree to compromise. When Mary informs Robbie of the plan, he tells her that it won't work between them. Fortunately for Mary, Robbie changes his mind after talking to Eric in the local grocery market. Also, Lucy gets into trouble after blowing off a Habitat for Humanity project to go on a date, and is caught. Meanwhile, Matt is consumed with depression due to Shana's upcoming move to New York. By this, Matt pays no attention to Simon, who just wants to spend time with his big brother. Also, Ruthie makes a vast millenium preparations until Eric provides her with a more grounded perspective.

Annie's father Charles shows up at the Camden household for a weekend visit as Ginger supposedly needs to get away for a bit. But Eric forgot to tell his wife about it and nearly everyone in the Camden household is too busy to spend time with the elderly man. So Grandpa Charles takes Simon to get his learner's permit for driving and they end up being the center of a televised police-pursuit. Eric lies to Annie about his plans for the day, which include a trip to Glenoak Hospital.

Matt and Eric meet with Rabbi Glass to discuss wedding plans, and Eric learns that he is playing a smaller role than he had originally planned. Annie prepared for fewer guests to attend the rehearsal dinner and gets very flustered when she does not have kosher food. Ginger and Charles are prepared to fly to Glenoak, but Charles get's lost at the airport. Simon gets angry when Matt asks Robbie to be his best man. Meanwhile, Ruthie tells Robbie that she wants his room for herself after Matt moves out. Ben proposes to Mary, but he gets an unexpected answer.

Matt and Sarah grieve over Eric's decision not to attend the nuptials following his argument with Rabbi Glass over Matt's conversion to Judaism. Hoping to patch things up between their fathers, Matt and Sarah seek their mothers' help in persuading them to put aside their differences before it's too late. Ben and Kevin come to Glenoak to meet up with Mary and Lucy so that they can resolve their problems. Robbie tries to figure out why Ruthie wants him to move out of the Camden household.

Annie's half-sister Lilly is getting married and wants their ailing father to walk her down the aisle but Annie worries that the strain might be too much for him. Meanwhile, Fred and Mrs. Bink attend premarital counseling with Chandler, but Fred's mother tries to put a stop to the wedding because she thinks Mrs. Bink is a gold digger. Lastly, Jimmy and Pat, two mentally challenged people, decide to get married after just one date and ask Chandler to perform the ceremony, but Jimmy's parents try to put a stop to it.