A year after losing their larger than life family patriarch and three weeks since hearing from Justin in the Middle East, the Walker family struggle to find cheer in celebrating Kitty's birthday. Sarah fights to salvage what's left of her failing marriage; Kevin learns the hard way about the sacrifices that true love brings; Tommy is at a loss as to how to provide the emotional support needed by his overwhelmed wife, Julia, after the death of their newborn son, while Kitty gets a first hand look at the challenges of being engaged to a U.S. senator (Rob Lowe as Senator Robert McCallister). Meanwhile, Saul questions his identity after a visit from an old friend, and the family's newest member, Rebecca, tries desperately to find her place in this very complex family puzzle.