Sam faces her hardest challenge yet: avoiding alcohol on St. Patrick's Day in Boston. Brit gives Sam an unexpected chance to rekindle their friendship. James and Mindy track down his lost keys while battling St. Patrick's Day temptations.

On her wedding day, Brit’s jitters lead her to make an unexpected decision. Carol and Bob take their relationship to a new level. Sam learns the truth about James and is shaken to the core about what her future might hold.