Still unemployed and bills mounting, Mary continues her downward spiral to rock bottom as Eric and Annie fight about how to effectively deal with her numerous lies and immature behavior. Meanwhile, the fear of what may happen to Mary starts to take toll on the rest of the whole family. By this, it is prompting the children to break open the twins piggy banks to help Mary pay her bills. To get the credit card company to stop calling, however, they are forced to make a risky decision. During all this, Mary CONTINUES to ignore her responsibilities.

As Annie plans a mysterious day of cleaning as Eric discovers the shocking news that Mary ran away from ""The Colonel""'s to come back home because of a devious scheme she had with Robbie and freaks out. Eric is convinced that more trouble is brewing and goes to insane lengths to find answers. In reality, Mary is heading home for a huge surprise birthday party for Eric, attended by all the people whose lives he's changed for the better in the past few years. Chores at home are interrupted, however, when Ruthie discovers Frankie and Johnny's baby, Mercy at the Camden front doorstep. Meanwhile, Lucy stays with her friend Mike's (guest-star Jeremy Lelliot) near catatonic mother for the day, and drops a proverbial bomb on Lucy. Also, Matt and Simon try to figure out why they delivered Mrs. Bink (guest-star Eileen Brennan) to the hospital.

Eric tries to arrange a romantic evening with Annie, but Annie keeps turning down every attempt he throws at her. At the same time, Annie takes Eric by surprise with the news that she would like to quit college and to start teaching to help get her out of her depression. Meanwhile, Simon is at risk of being fired from his new job at the pizza parlor by his excessive tardiness and discovering that waiting tables takes more people skills than he's equipped to handle. Also, Robbie sets Lucy on a date with one of his friends while Matt is concerned about a woman who keeps showing up at the clinic a lot. Lastly, Mary performs terribly in fire fighting training distracted by her consuming relationship with Wilson.

The Camdens, especially Lucy and Ruthie, grow concerned that an unusually joyful Annie isn't dealing with her true emotions following the death of her father Charles, but the happiness proves to be infectious as it soon spreads through the family and all over town. Meanwhile, Eric tries to convince an unhappy Chandler that he should consider adoption. At the same time Chandler is approached by a mysterious young girl who gives him a cryptic message before she disappears.