S4, E4: 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 when it is revealed that Sammi isn't a match for a transplant. Lip continues to struggle with the full plate in front of him and shows up at Mandy's out of loneliness, while Debbie's age difference with Matt puts their relationship on the rocks.