When father-and-son (guest stars Robert and Andy Prosky) come to the ER, Luka must treat the son’s failing heart while he takes on responsibility for the father. Language presents a challenge when Neela and Abby treat a good Samaritan. Meanwhile, Pratt tries to help Chaz make a new career choice, Gates has troubles with his own father, and Sam’s got her hands full with a seminar on handling aggressive patients. And who’s the John Doe Abby’s treating, and hiding from Luka?