As the holiday season passes, Miranda is visited by her father, who disapproves of her life choices; Mark and Lexie must cope with the arrival of a woman from his past; Thatcher questions the chief's recent behavior.
George's father has surgery for his cancer; Thatcher Grey arrives to see his new granddaughter; Meredith finds that Derek has trouble sleeping.
Meredith and Lexie's father returns to Seattle Grace with stomach pains and a new girlfriend; Alex butts heads with the new OB; Mark bribes Jackson for information on Lexie.
Someone from Derek and Addison's past arrives in Seattle; Burke learns Christina's secret; Meredith looks into her family's dirty laundry after a visit with her mother.
Addison takes a temporary leave from Seattle Grace and visits old friends in Los Angeles; Cristina reluctantly plans her wedding with help from Burke's mother (Diahann Carroll) and her own; Derek must perform surgery on Jane Doe.