Next week on Grey's Anatomy, Thanksgiving, Christmas and New Year's pass, Miranda is visited by her father, William, who disapproves of her choices in life. Meanwhile, Thatcher Grey questions the Chief's recent behavior as Meredith, of all people, comes to his defense.

Perhaps most significantly, Mark and Lexie cope with the shocking arrival of a woman from his past - a girl who looks to be about 18 and claims Mark is her ... wait for it ... dad!

Is it true? Will this set the Private Practice crossover in motion? It sure does look that way. We'll have to wait and see, but this could be a very interesting development.

Check out the promo for next week's "Holidaze" and see what you think ...

[video url="http://www.tvfanatic.com/videos/holidaze-promo/" title="Holidaze Promo"] [/video]

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.