Sam and Luka go on the search for her runaway son, Alex. Meanwhile, Pratt and Lewis guide Abby, Neela and Ray, who have become R2's, on how to teach the new interns.
Quest roles:
Troy Evans(Frank Martin), Yvette Freeman(Haleh Adams), Dominic Janes(Alex Taggart), Sara Gilbert(Jane Figler), Kyle Richards(Nurse Dori Kerns), Corey Stoll, Michael Spellman