The FBI arrives in Southold, complicating Jo's efforts to find Emily. Meanwhile, Alex and Piper hunt for answers on a road trip, and the family celebrates Mia's birthday.

Cast: Ashley Aufderheide, Robert Bailey Jr., Seth Barrish, Clancy Brown, Maria Dizzia, Donald Faison, Rowena King, Alexa Swinton, Allison Tolman, Dana Wheeler-Nicholson, Owain Yeoman, Evangeline Young