Cameron feels competitive when a popular teacher returns from sabbatical; Haley goes to a realtor's banquet with Phil; Mitch struggles to get his bearings at his new job; Jay and Gloria babysit Lily.
Derek and Meredith adjust to life at home with their newborn; Arizona tries to repair her marriage; Jackson and Owen clash over financial issues.
A series of strangulations leads the team to look for a killer who keeps mementos of his victims; Rossi's favorite bar is in danger of closing.
Addison's father's arrives in Los Angeles, which rattles her; after refusing to cooperate in a case involving a longtime patient, Cooper is arrested; Pete fights to keep a terminally ill patient alive long enough for him to meet his new daughter.
A ghost warns Melinda that a bomb missing from a hidden munitions dump will cost someone's life.