Fiona and Mike take a big step forward when Mike invites her to dinner with his family. She meets his parents and older brother, who is a thrill seeking ex-alcoholic. Debbie fools Shelia into thinking she is at a sleep over party, and sneaks out for an evening with the new boyfriend. Frank is setting up a "chance" meeting with eldest daughter Samantha to try to scam her into giving him a piece of her liver. Meanwhile, Carl trying to keep Frank in pain killers and the family with food on the shelves concocts a scheme to make some extra cash.
Against her better judgment, Fiona continues her secret affair with Robbie. And the situation nearly boils over, when Mike shows up at Robbie's apartment while Fiona's inside. Fiona is able to hide just in time before her infidelity can be exposed. In increasingly dire health straits due to liver disease, Frank attempts to contrive an "accident" that will provide an ample insurance payout to cover the cost of a potential transplant. Too physically weak to injure himself, he enlists the help of an overeager Carl. With the odds stacked against him, he gets more bad news...
Fiona's bad decisions involving Robbie finally boil over. Frank and Sammi continue fixing his liver trouble, while catching up on the father-daughter time that Sammi always wanted. Lip gets a surprise at college from Army investigators.
Fiona starts to go nuts while under house arrest. Ian shows up at home. Carl almost gets expelled from school, but gets helped out by Frank. Debbie starts to become a woman and connects with the "other sister"
Fiona gets off house arrest. Lip runs into some "big" issues at school. Ian and Mickey blackmail rich old family men, and Carl finds true love in detention, in a girl who is just as messed up as he is. Debbie is jealous of a new girl.
Fiona goes on a heavy bender and ends up in Wisconsin and Lip has to come rescue her. Mickey and Kev start fighting over their joint venture. Bonnie and Carl steal a car. Sammi and Sheila try to find Frank a cheap liver transplant.
Frank suffers post-operative delirium after his liver transplant. Fiona starts 90 days in jail. Lip irritates Amanda's parents and receives a generous payoff to leave her. Debbie is humiliated at school by an older boy.