Barney concocts a plan when his father (John Lithgow) arrives at the hotel; Ted thinks he is being framed when a wedding-related duty gets messed up.
During a murder investigation, the team uncovers a fraudulent charity targeting those looking for missing military personnel; Tony considers adopting a stray cat that followed him home.
Dawn has had enough of her brothers' gross out antics and finally gets her own room. It's a dream come true until the quads realize they need each more than they think.
As The Quad's 10th birthday approaches they decide it is time for them to have individual, "grownup" parties. They each plan their own party, but quickly discover that maybe they're not in such a hurry to grow up.
Meredith keeps herself busy while Derek prepares for his move; Jackson and April get difficult news; Arizona and Amelia talk about how best to approach Dr. Herman.